480 SUMMARY OF CURRENT RESEARCHES RELATING TO 
y. Gastropoda. 
Phytogeny of Gastropods.* — Dr. Guiart seeks to modify somewhat 
the phylogenetic arrangement of the Gastropoda and of the Opistho- 
branchs in particular. His scheme, based on the disposition of the 
nervous system, is the following : — 
PODONEURA 
Gymnosomata Notarchus 
Thecosomata Lobiger 
Acteonid se 
I . 
Prosobranch Monotocardia (Aponotoneura) 
Prosobranch Diotocardia (Epipodoneura) 
Aplysiidae 
i 
Acera 
Bulleidje 
Acteon 
Noton eur a 
Nudibranchs 
Pleurobranchs 
Tylodina 
Arthropoda. 
a. Insecta. 
Protective Adaptations in Insects. f — Prof. S. D. Judd has ex- 
amined the stomach contents of fifteen thousand birds in the United 
States, and writes a very interesting article on the value of the pro- 
tective adaptations of insects with special reference to colour. From 
the nature of the paper a detailed abstract is not easy, but the following 
are some of the observations and conclusions contained in it. Insects 
which resemble the substratum on which they rest are not necessarily 
protected by this resemblance ; thus protectively coloured grasshoppers 
are habitually eaten by over three hundred species of birds in the 
States, and in many cases the birds eat stationary and not moving 
specimens. Similarly the admirably “protected” weevils are eaten 
by numerous birds, and so with other protected forms. Hairs and 
stings, on the other hand, seem very efficient in protecting their possessors 
from attack. Insects furnished with nauseating fluids are not invari- 
ably avoided, whether their colours be bright or not ; but the families 
Coccinellidae and Chrysomelidse, which include showy ill-scented insects, 
are usually avoided. As to warning coloration and mimicry, there is 
* Bull. Soc. Zool. France, xxiv. (1899) pp. 56-62 (6 figs.), 
t Amer. Nat., xxxiii. (1899) pp. 461-8*. 
