ZOOLOGY AND BOTANY, MICROSCOPY, ETC, 673 



the case of the aphides the coefficients of variation for meristic varia- 

 tions are notably large — as large as those in mosquitos, ants, etc., where 

 amphimixis is the rule. "Amphimixis is not only not necessary in order 

 to insure Darwinian variation, but there is no evidence that I am aware 

 of to show that it increases this variation." 



Mutation in Mosquitos.* — S. E. Weber gives an account of some 

 very remarkable observations, the nature of which may be gathered from 

 the following samples. From a mass of 352 eggs deposited by CuJex 

 pipiens, 43 adults were reared. " Three of these were C. restuaiis 

 Theobald (females), two were a variation from C. restuans, females, and 

 two others, also females, were of the same beautiful deep, cherry-reddish- 

 brown tint with all the other parts as to colour and size like the G. 

 restuans and variation, but did not have the scaled spots on the dorsum." 

 The identification of the C. restuans was confirmed by D. "W. Coquillett, 

 of the U.S. National Museum. Other results obtained were Culex 

 pipiens and C. restuans larvas from eggs of G. salinarius Coquillett, 

 which larvfe reverted to G. salinarius adults ; G. restuans eggs and 

 larvic which produced G. pipiens adults ; G. pipiens larvas and adults as 

 mutants from G. salinarius eggs ; and so on. " We have in these 

 phenomena of changes the process or scheme of nature by which new 

 species are produced." 



Fenestrae of Periplaneta orientalis.f — B. Haller has investigated 

 the structure and nerve relations of these bodies, and concludes" that 

 they are degenerate ocelli which no longer function in light perception, 

 but constitute a special sense-organ. There is no doubt that they are 

 homologous with the ocelli of other insects. 



Sarcophaga Larva in Human Intestine. | — E. Warren records the 

 occurrence in the intestine of two Europeans in Natal of fly larvse, one 

 of which on being bred out proved to belong to the genus Sarcophaga. 

 The species is undetermined. The larva possesses no special organs for 

 adhering to the mucous membrane of the alimentary canal, and it is 

 possible that the parasitic habit is purely accidental. It is certain that 

 in the case from which the fly was bred no flesh was eaten, but as large 

 numbers of larvas have been seen escaping from the body of a female of 

 a Sarcophaga without any apparent effort on her part, the contamination 

 of food-stuffs such as bread, by the minute white grubs, is easily con- 

 ceivable. 



Internal Metamorphosis of Trichoptera.§ — H. Liibben describes 

 the phenomena of metamorphosis as observed in the gut, respiratory, 

 and sexual organs. Some of the internal larval organs develop pro- 

 gressively onward to the imaginal state, e.g. the sexual organs ; others 

 undergo histolysis, to be reconstituted in the pupa stage, e.g. the 

 muscles. The trachete occupy an intermediate position as regards these 

 processes, since in the Trichoptera they in some part degenerate and in 

 others persist. 



* Weber's Archives, i. (1907) No. 2, Lancaster, Pa., pp. 1-28 (6 figs.). 



t Zool. Anzeig., xxxi. (1907) pp. 255-62 (4 figs.). 



X Ann. Natal Govt. Museum, i. (1907) pt. 2, pp. 215-8. 



§ Zool. Jahrb , xxiv. (1907) pp. 71-128 (3 pis.) 



