112 HALF-AN-HOUR 



Aphis (PI. 30, upper half). — The principal points shown in 

 this preparation are the eye, the parts of the mouth, the limbs, and 

 the contained ova. " As choke full of young uns as an egg is of 

 meat," might fairly be said of it, so that, I think, it will hardly 

 do to speak of her as a he! It is difficult to make out either the 

 abdominal segments or the spiracles ; the whole abdomen seems 

 just converted into a bag of eggs. We subjoin a drawing of the 

 chief points of interest. 



Larva of Caddis (Leptocera) (Plate 30, lower half). — The 

 lucid notes on this slide (see page 124) render it superfluous for 

 me to say anything further. So I shall merely add that West- 

 wood gives a large amount of interesting detail on these forms. 

 In Science Gossip for July, 1868, is a paper on their Cases by R. 

 McLachlan, accompanied by various illustrations. At the same 

 date appeared in Popular Science Review an article on the Flies 

 and their larvae by the Rev. W. H. Houghton ; this gives a good 

 general view of the subject. 



There are notes on Caddis larvae extracted from Rev. J. G. 

 Wood's "Homes without Hands," in Sci. Goss., 1866, p. 95, 

 and on Caddis Worms by M. Pope in the same vol., p. 189. A 

 very interesting paper with references to experiments by Miss Smee 

 (Pop. Sci. Review, Jan., 1864) on cases built of different coloured 

 materials. One of M. Pope's was of broken glass, beautifully 

 translucent. Others on the same subject (I think by Helen E. 

 Watney) have also appeared in Sci. Goss. The plan with red 

 Coral is a capital notion. Too much stress must not be laid on 

 species invariably building their cases of one kind of material ; 

 individuals occasionally employing (even in a state of nature) 

 what comes nearest to them when engaged in their construction. 



I should like to call the attention of our members to a 

 communication in Sci. Goss. for July, 1867 (p. 167), in which the 

 attacks of Caddis larvae on small fishes would appear to have 

 been attended with a venomous effect * ; the subject is one which 

 it would be desirable to examine further into. The materials 

 composing the cases are attached by the assistance of silken 

 threads, which they spin from the mouth in the same manner as 

 caterpillars. The spinneret is said to be minute, and to be seated 

 between the basal joints of the anterior pair of limbs, but further 

 investigation into this seems to be required. 



Acari from Chaffinch (PI. 31, Figs, i, 2). — These belong 

 to a highly interesting group, the Itch-mites. One species, 



* I have seen this happen in two instances this month, June, 1883. — E. T. Stubbs. 



