Vol. XYI. No. 403. 



THE AGRICULTUKAL NEWS. 



309 



and there would be little fo'd for the pest from februiry 

 to July. 



lo connexion with (b) it may be mentioned that the 

 most sAiisfactory method of killing the stainers which collect 

 on the cotton s- ed traps is the use of a gasolene torch. After 

 a few minutes" appliiation most of the insects were killed, 

 and it was found that burning does not destroy the effective- 

 ness of I he cotton seed as a trap, as kerosene oil does. Cotton 

 seed was found to be a more eflfeclive trap than either silk- 

 cotton pods or cotton seed meal. 



The natural tnemies of the stainer include birds, ants. 

 and a species of mite. The 'Pipiri' or 'Hawk-beater' 

 (Tyranmis rostratus) eats a large number of stainers, as 

 examinations of stomach contents showed. The blackbird 

 (Crotophaya aiiij and domestic few's consume a limited 

 number. 



The common small black stinging ant {Solenopsis 

 gtminata), and the hunting 'tac-tac' ant (Odontomachus 

 haematodes) both carried off the eggs readily, while the small 

 red stinging ant (undetermined) frequently tried to do so, 

 but failed. The crazy ant or 'Wild Irishman' (Prenolepis 

 longicornis) was strongly repelled by the eggs. No egg 

 parasite has been observed. 



.ADAPTATION AND THE PHYSICAL BASIS 

 OF BIOLOGICAL CHARACTERS. 



In the course of a series of four Croonian Lectures 

 delivered at the Royal College of Physicians London, in 

 June hist. Professor J. G Adami put forward some new 

 biological conceptions of much importance. In the first 

 place he raised the question whether variation is inherent, 

 proceeding from within, or whether it is acquired, proceeding 

 from without, rie charged biologists with largely neglecting 

 this aspect of the inquiry into methods of evolution, and 

 with directing attention almost exclusively to the secondary 

 problem of the transmission jf acquired properties to the 

 offspring. After discussing the attitude of workers such as 

 Herbert Spencer, Weismann, and Bateson towards these 

 problems, he statid that valuable and fascinating as are the 

 studies for the establishment and amplification of Mendel's 

 law, that law deals only with the combinations and permuta- 

 tions of positive a- d negative unit properties possessed by 

 the species; it establishes only the extent of variation possi- 

 ble within the species. The study of immunity, and the 

 problems of pathogenic bacteriology lead to the conclusion 

 that bacteria manifest direct adaptation, i.e., specific modifi- 

 cation in I espouse to specific alteration in environment, that 

 is to say, change of environment gives rise to new species. 

 He point s out that there is, for example, abundant experi- 

 mental evidence of adaptation of bacteria to new food- 

 stuffs, to foreign sugars, glucosides, fats, ttc. The bacteria 

 taking on these new powers must be regarded, not as 

 mutants, but as new species arising from the influence ef 

 a particular environment. In a similar way, the acquire- 

 ment of virulence in the case of a bacillus, derived by 

 Thiele and Embleton from the harmless saprophytic form 

 B. mt/coides, must be regarded as permanent chmge arising 

 from the eflfect of environment, that is, direct adaptation. 



The creation of immunity towards specific dLwases on 

 the part of the higher animals arises from adaptive changes 

 produced in certain body cells, whereby they have acquired 

 pew habits under the influence of environmental changes ; as 

 the result of these changes, the cells are able either to destroy 

 invading organisms or to inhibit their growth. These changes 



result in the establishment of a regular habit on the park 

 of the affected celLs, the cells are impressed with new prop- 

 erties. Immunization is direct adaptation. 



Of very great interest to general biologists is the lec- 

 turer's s'lggestion as to the mechanism by means of which, 

 individual properties and characteristics are carried and 

 transmitted. Darwin discussed the possibility of thesa 

 properties being carried by specific atomies diffused through 

 the body structure, the pangenesis hypothesis, but he aban- 

 doned this as untenable. Other workers, such as Weismann, 

 have postulated the existence of specific carriers of properties, 

 and have suggested the existence of specific ids, idants, and 

 determinants ; while Mendelian students are disposed to the 

 idea that the chromosomes of the nucleus are the specific 

 carriers of individual characters, but ihey find difficulty ia 

 conceiving how such limited bodies can carry the multiplicity 

 of characters involved in every organism. 



Professor Adami suggests that these difficulties disappear 

 if we regard the protoplasmic contents of the germ cells as being 

 the agencies involved in this work of transmission ; he 

 points out that there are many forms of protoplasm, and 

 that the molecules even of the simplest types are of a mar- 

 vellous degree of complexity, containing from 700 carboa 

 atoms in the molecule, in the case of the relatively simple 

 haemoglobin, to many times this number in the more com- 

 plex forms. 



It is well known that in the case of complex carboa 

 compounds, marked change of properties results from modifi- 

 cation in the manner in which the atomic grouping takes place. 

 Even in the case of the simple sugars of the hexose group 

 containing but six carbon atoms, modification in the manner 

 of atomic grouping gives rise to sixteen different forms of 

 sugars exhibiting different properties. There is little difficulty, 

 therefore, in conceiving that molecules containing frora 

 700 to 1,000 carbon atoms admit of an immense num- 

 ber of possible groupings, and, consequently, of exhibiting 

 an immense number . of characters or properties, which 

 properties may exhibit themselves in the structure and 

 function of the organisms in which the various protoplasms 

 exist. 



If we imagine that the various characteristics exhibited 

 by different organisms are dependent on the nature and 

 structure of their constituent protoplasms, there is no 

 difficulty in thinking that the possible forms and combinations 

 are numerous enough to carry and transmit all the individual 

 characters of various organisms. 



THE PRICE OF WHEAT AND FLOUR. 



The American Consul at Barbados has communicated 

 the following to this Department as the official order of 

 the President of the United States: — 



'Section 11 of the Food Act provides, among other 

 things, for the purchase and sale of wheat and flour by the 

 Government, and appropriates money for the purpose. Tha 

 purchase of wheat and flour for our allies, and to a consid- 

 erable degree for neutral countries also, has been placed[ 

 under the control of the Food Administration. I have 

 appointed a Committee to determine a fair price to be paid 

 in Government purchases. The price now recommended by 

 that Committee— ?2-20 per bushel at Chicago for the basic 

 grade — will be rigidly adhered to by the Food Adminis- 

 tration'. 



