Imágenes de páginas

Triticum Polonicum (harvested, 1895).

Strength = 54:0
custom Swet = 36:04

my dry = 13.20 The gluten of this wheat is soft, inelastic, adhesive, not very coherent. Gluten consists of glutenin = 9.91

gliadin = 3.29
or glutenin = 75 per cent. in gluten.

gliadin = 25
Australian Poulard (harvested, 1895).

Strength = 47° 8
Gluten | wet = 28.01

ndry = 9.80 The gluten of this wheat is soft, inelastic, very adhesive, non-coherent. Gluten consists of glutenin = 6:94

gliadin = 2.86
or glutenin = 70-8 per cent. in gluten.
gliadin = 29.2


Bancroft (harvested, 1895).

Strength = 57.2
Gluten wet = 26:80

dry = 9:51 The gluten of this wheat is soft, inelastic, adhesive. Gluten consists of glutenin = 5.91

gliadin = 3.60
or glutenin = 62-2 per cent. in gluten.

gliadin = 37.8 , Improved Fife was selected as being of a similar nature to Hornblende, no grain of this latter variety being available. No grain of the class represented by Toby was obtainable from the 1895 harvest, and comparison of this wheat was, therefore, unfortunately impossible. Bancroft is a very peculiar Durum wheat, and is the only one I have met with which yields a fairly strong flour, whilst its gluten is sticky and inelastic. It was examined here in order to see whether the chemical nature of the gluten would clear up the anomaly. It will be seen that the gliadin is high, as in the other adhesive gluteng.

A comparison of the results obtained by the Fife wheat and by Triticum Polonicum and the Poulard, harvested in 1896, with the same wheats harvested in 1895, show the influence of the proportions of the proteids in a very striking manner.

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Imperial Fife in 1895, and

Hornblende in 1896 ... Triticum Polonicum Australian Poulard


1896 1895 1896 1895 1896

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9.80 12.97

29.2 35.9

In all the above cases the flour obtained from the wheat harvested in 1896 contained more gluten than that from the 1895 harvest, but was in all cases a weaker flour, and this appears to be characteristic of this season's harvest. This is directly opposed to the assumption that the gluten content and the strength are interdependent. The explanation is found in the columns giving the proportions of glutenin and gliadin in the gluten. It will be seen that the glutens of the 1895 wheats are all richer in glutenin than the 1896 wheats.*

An examination of the separated proteids glutenin and gliadin for their individual power of absorbing water gave the following results. The glutenin and gliadin from four of the glutens, after being dried and weighed, were soaked in water until they were thoroughly saturated, the excess of water drained off, and the proteid superficially dried as well as possible :8.89 grammes dry glutenin from Hornblende gave 15.89 grammes wet

glutenin; absorption = 78.7 per cent. 8:32 grammes dry glutenin from Australian Poulard gave 15.28 grammes

wet glutenin; absorption = 78.2 per cent. 4:18 grammes dry gliadin from Toby gave 6-76 grammes wet gliadin ;

absorption = 38.2 per cent. 6:02 grammes dry gliadin from Triticum Polonicum gave 8.96 grammes

wet gliadin; absorption = 43-5 per cent. These results, though they agree with the results previously obtained, and show that glutenin is capable of absorbing water to a considerably greater extent than gliadin, are nevertheless not quite satisfactory on account of the difficulty in removing the surface moisture of these proteids, especially of gliadin. I leave them, however, subject to future correction, as they are 3 sort of check on the previous work,

The experiments here recorded point to the following facts :

The strength or water-absorbing capacity of a flour depends directly upon the relative proportion in which the two proteids are present in the gluten.

If the gluten contents of two flours be nearly the same, that will be the sironger four which contains the larger proportion of glutenin.

Flours in which glutenin preponderates yield strong, tough, elastic, nonadhesive glutens.

Increased gliadin content produces a weak, sticky, and inelastic gluten.

Appended is a table giving the results in a concise form. For the sake of comparison, the gluten and strength of the 1894 grain are included. It will be noticed that there is a considerable difference from year to year in the nature of one and the same grain. Both gluten content and strength of flour vary in different years, a fact which is no doubt attributable to the nature of the seasons.

It is to be regretted that a larger number of wheats could not have been experimented with. The absence of Purple Straw, which is the variety most largely cultivated at present in the Colony, is particularly regrettable. It is, however, fairly well represented by Toby. Those examined represent, moreover, types of grain with well-marked characteristics as to strength and gluten content, and it was to be anticipated that these would exhibit differences in constitution more distinctly than would grains more nearly resembling each other. Moreover, these could not be obtained until the harvest of 1897, and the results here given are, I think, sufficiently definite to justify my bringing them before notice without waiting until next year.

• It should be stated, in connection with this matter, that the season of 1896 was excessively hot and dry. The season of 1895 was, however, of the same character during the time when the grain was being formed, but the soil was less dry than in 1896. It will be interesting to examine the gluten contents, and the composition of the glutens of the same wheats after a season of an opposite character to that of 1896.

Variety of Wheat.

of Iar

Nature of Gluten.



Glutenin. Gliadin.

Peroen Percen

tage of | tage of Glutenin Gliadin in Gluten, in Gluten.

Proportion of
Glutenin to


Improved Fife ...

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... 1894


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Triticum Polonicum




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Australian Poulard



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| Soft, non-adhesive ... ... ...
Tough, elastic, non-adhesire, coherent ...
Soft, very adhesive ... ... ...
Soft, inelastic, adhesive, not very coherent
Soft, inelastic, adhesive, non-coherent ...
Very soft, very adhesive ... ... ...
Soft, inelastic, very adhesive, non-coherent
Very soft, inelastic, very adhesive, non.

Medium soft, medium elastic, and coherent
Soft, medium elastic, non-adhesive,

medium coherent.
| Hard, non-adhesive, coherent... ...
Medium hard, elastic, fairly non-adhesive,

fairly coherent.
Medium hard, non-adhesive, coherent ...
Soft, inelastic, adhesive ... ... ...

100 : 56

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Assistant Entomologist, Department of Agriculture, New South Wales.

Introduction. So much general interest has been awakened in ticks throughout the Colony by the serious losses consequent upon the appearance of the cattle tick, and the malignancy and rapid spread of Tick-fever in Northern Queensland, that a few notes upon these pests may prove acceptable to many readers of the Agricultural Gazette. The cattle tick has already received attention in a former number of the Gazette, and although it will, without doubt, be found necessary to refer to it again, the subjects for immediate consideration will be a number of ticks which correspondents have forwarded to the Depart. ment of Agriculture for determination. These specimens bave always been accompanied by the anxious inquiry : “Is it the Queensland tick?” and by far the larger number of them consisted of a species of Argas which infests poultry.

Before proceeding to discuss this pest in detail, it may not be altogether out of place to consider the position of "ticks" in the animal kingdom, and the relation they bear to the other members of the family to which they belong. : Zoology is the science or study of the habits and structure of animals, and the sorting out or arranging of them together into groups is called "200logical classification."


these again into Orders, the orders into Families, the families into Genera, and the genera into Species.

Thus, for example, we have a large number of dogs exactly alike, such as the Newfoundlands. These constitute a Species.* Then we have the Australian dingo, or wild dog, which forms another species called familiaris. australis, and then again there are the wolves, constituting the species lupus.

These three species, with others, form a Genus called Canis, which is closely related to the genus Vulpes (the foxes); and the genus Megalotis (containing the dog-like fennecs of North Africa).t

* It is now generally believed that the majority of the numerous “breeds" of domestic dogs are varieties, all descended from a common ancestor-probably a domesticated wolf

+ It is usual when referring to an animal to give both the name of the genus and the species. The name of the genus-which may be likened to a surname-is always followed by the specific name, which supplies the baptismal name. For instance, the dingo belongs to the genus Canis, and the species familiaris-australis. It is, therefore, always referred to as Canis familiaris-australis, which is the Latin for the native dog of Australia.

The three genera, Canis, Vulpes, and Megalotis, make up the Family Canide (the dog family). The dog family has amongst its relations the Felide, or cat family (cats, tigers, lions, &c.), the Hyanide, or hyæna family, and the Mustelidæ, or weasel and badger family.

These families, together with the bear family and others, constitute the Order Carnivora, or flesh-eaters.

Of the numerous Orders, some of the best known are the Insectivora, or insect-eaters (ant-eaters, porcupines, &c.); the Marsupialia, or pouch-bearers (opossums, kangaroos, &c.) ; the Rodentia, or gnawers (rats, mice, &c.), which, together with the Carnivora, are grouped together, and form a Class, Mammalia, the members of which, it will be noticed, are all animals which suckle their young.

There are only four other Classes :-(i) Aves-feathered animals, which lay eggs and hatch them by the warmth of their own bodies (the birds); (ii) Reptiliascaly-coated creatures which lay eggs, leaving them to be incubated either by the heat of the sun or that arising from decaying vegetable matter (snakes, lizards, turtles, &c.); (iii) Amphibia-slimy-skinned animals, which in their young stages are fish-like, living in water, and breathing through gills, but which subsequently acquire true lungs, and develop limbs suitable for locomotion on land (frogs, newts, &c.); (iv) Pisces--those scaly or naked animals, which live all their lives in water, and breathe through gills (the fishes). These five Classes collectively form the great sub-kingdom Vertebrata, and include all animals possessed of back-bones and true skeletons.

The sub-kingdom Vertebrata has been purposely chosen to illustrate the outlines of classification, because its members, if not numerically the greatest, are certainly the most conspicuous and best known to everybody, whereas the other sub-kingdoms, in their different ramifications, are more or less obscure to any but the scientific investigator.

Classifying "Ticks.” In order to determine the position of these small animals, it is necessary to consider another sub-kingdom called Arthropoda, which, in point of popular knowledge, comes nearest to the vertebrates.

The term is derived from two Greek words, arthron, a joint, and pous, a foot. The sub-kingdom comprises those animals with jointed limbs, having no back-bones or true skeletons; they have, however, an external skin composed of a hard, horny substance, which takes the place of the true skoleton seen in the vertebrates, and to the inner surface of which the muscles arc attached.

This outer shell is made up of a series of segments or joints, and is spoken of as the “ pseudo-skeleton.”

The sub-kingdom Arthropoda is naturally divided into four well-defined classes :-(i) Insecta (true insects); (ii) Myriopoda (centipedes and millepedes); (iii) Arachnida (scorpions, spiders, and mites); and (iv) Crustacea (crayfish, crabs, and lobsters).

Many Arthropoda are spoken of as “insects,” and for the purposes of economic and popular entomology, it is a suitable designation. The off-told story of the railway official who allowed a pet tortoise to travel free, because it was an “insect," illustrates one of the many curious uses to which the word is often put.

Strictly speaking, the word “insect” is only applied to the members of the class Insecta, those jointed-limbed animals which have the body divided

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