1886.] Entomology. 973 
ENTOMOLOGY. 
KRAEPELIN ON THE ORGANS OF SMELL IN ARTHROPODS!— 
To Leydig it was first given to make a decided step in ad- 
and Hemiptera, and which had only thus far been regarded as 
sense-organs, Leydig first calls attention to the widely-distributed 
pegs and teeth, also considering them as sense-organs. “ Olfac- 
tory teeth,” occurring as pale pegs, perforated at the end, on the 
Surface of the antennz of Crustacea, Myriopoda, Hymenoptera, 
Lepidoptera, Coleoptera, are easily distinguished, and besides the 
‘olfactory pegs” of the palpi, may be claimed as organs of smell. 
‘Ne nerve-end apparatus first discovered by Hicks in the halteres 
and wings, Leydig thinks should be ranked as organs of hearing. 
Regarding the Crustacea, Leydig, in his latest work,* gave a 
lasting explanation of the nature of the pale peg or cylinder on 
the end of the antenne which he found in new groups of this 
class, which was adopted by a large number of naturalists. Thus 
Claus,> in his different essays, expressed the view that these Ley- 
digian organs had the function “ of making sensible slight changes 
” 1 bd “4 
In the chemico-physical condition of the water. ndeed, in his 
* Translated by A. S. Packard. Concluded from p. 894. 
4 ee “ Zum feineren.Bau der Arthropoden, Miiller’s Archiv, 1855, 376-480 ; 
Anatomie der Insekten, Archiv fiir Anatomie, 1859, pp. 35-89 and 149-183; 
Lehrbuch der Histologie, 1857, 220. i 
* Thes urring i d already been well de- 
k pegs, as occurring in Asellus and Daphnidæ, had already been we 
Scribed, in 1860, in his unke “ Naturgeschichte der Daphiden,” Tübingen, 
1860, without, however, a discussion of the question whether they were olfactory 
organs, 
a hy dig: Ueber Amphipoden und Isopoden, Zeits. f. w. Zoologie, xxx, 1878, 
o SH. 
-> Claus + Ueber die Organization und Verwandtschaft der Copepoden, Wiirzburg, 
1862, 19; Die freilebenden Copepoden, Leipzig, 1863, 55. 
$ Claus: Entwicklun Organization und Systemat. Stellung der Arguliden. Zeit. 
E w. Zool., 1875. tar Konatas der Organization und des feineren Baues der 
Daphniden, etc. Zeits. f. w. Zool., 1876. Zur Kenntniss des Baues, und der Or- 
‘Sanization der Polyphemiden. Denkschr. d. Wiener Akad. wiss. Math. 
Classe, 1877, xxxvit, 245. Der Organismus der Phronimiden, Wien, 1879, 10. 
aa a 
