456 SUMMARY OF CURRENT RESEARCHES RELATING TO 



sternum, give evidence of a fusion between two primary metameres in 

 the Hcxapoda and Chilopoda. In HexapodaaDd Chilopoda, the anterior 

 metamere bears the functional, and the posterior the rudimentary leg. 

 Neuroptera are most generalised in the development of the coxa]; in 

 Thysanura and Orthoptera there is high specialisation. 



Influence of Light on Coloration and Development.* — Herr D. 

 Neniikow has experimented with the eggs and larvae of Pieris rapse, 

 which he reared under light passing through solutions of various colours. 

 The development was most rapid, both as a whole, and in its component 

 periods, under the influence of ordinary white light. After white light, 

 the order of advantageousness is red, violet, green. But under the 

 green rays the development was markedly retarded, and there was great 

 mortality. Neither with Pieris rapse nor with Vanessa urticse was any 

 change in the coloration of larvae, pupae, or adults observed as the result 

 of development under red, violet, and green rays. 



Role of Insects in Spread of Disease.f — Dr. G. H. F. Nuttall has 

 published a critical and historical study on the role of insects, arachnids, 

 and myriopods in the spread < f bacterial and parasitic diseases of man 

 and animals. Beginning with an account of experiments made to de- 

 termine the i 61c of flies in the spread of anthrax, he goes on to cholera, 

 tuberculosis, malaria, &c. Ixodidae, Argas, Sarcopsylla penetrans, and 

 Trombididae are also discussed ; and what we may call a chapter (in a 

 long paper whose arrangement is not very clear), is devoted to the 

 diseases of insects, &c, due to animal parasites. There is a long biblio- 

 graphy. 



Clinical Entomology 4 — Dr. J. Ch. Huber has done a useful piece 

 of work, a reference to which may be of service, in making a bibliography 

 of the Pediculidae, Diptera, and A carina parasitic in or on man. ,The 

 woik will form a valuable supplement to the author's bibliography of 

 clinical helminthology.§ 



" Cilia" in Intestine cf Insects. ||— Dr. L. Bordas points out, in re- 

 ference to a paper by M. Lecaillon H on "cilia" in the mid-gut of the 

 gnat, that he has described these curious non-motile protoplasmic pro- 

 longations of the epithelial cells in several of his papers, both in the 

 mid-gut itself and in the pyloric caeca. He believes that they occur^in 

 the mid-gut of all insects. 



Structure of Nucleolus in Insect Hypodermic Cells.** — Mr. T. F. 

 Montgomery describes the nucleoli of the resting hypodermic cells of 

 the larva of Carpoeapsa pomanella as displaying what he has already 

 described as " chromatin nucleoli." In undifferentiated hypodermic 

 cells the nuclei contain true nucleoli (plasmosomes), but in the modified 

 cells which cover the feet, " chromatin nucleoli " appear in close ap- 

 proximation to the true nucleoli, and, except in their greater affinity for 

 stains, resemble ordinary chromatin granules. They are apparently 

 produced by the modification of chromatin granules. Similar " chro- 



* Physiol. Russe, i. (1899) pp. 244-.*0. 



t John* Hopkins H. sp. Kep., viii. (1899) pp. 1-154 (3 pis.). 

 t Jena, 1899-' 900, 4 Hefte. § Miinchen, 1890-1894, 8 Hefte. 



II Bull. Soc. Ent. France, 1900, pp. 25-7. f Tom. cit, 1899. 



** Zool. Jahrb. (Abt. Anat.), xiii. (1900) pp. 385-92(1 pi.). 



