INSECTA. 
153 
Generationen, eine eigentliiimliclie Form der Brutpflege in 
den niedern Tliierclassen. Copenhag. 1842, 8vo., has attracted 
the attention of zoologists in a great degree. 
In the articulated animals, the author recognises (p. 121) the phe- 
nomenon of the varied generation, only in the change of the swarms of 
the aphides, which lay eggs and also produce living young ; but he finds 
also an allied phenomenon in the peculiar nursing swarm of wasps, bees, 
ants, and termites ; the phenomena of life, however, arise in such variety 
and fulness in these classes of animals, that it is almost to be expected 
similar varied generation will also be discovered in other families, as 
soon as the attention of observers is directed to it. The propagation of 
gall flies (Cynipsera) at least in one respect deviating from the rule, 
might next richly merit the attention of physiologists (v. infr.) 
We have followed, with interest, inquiries on the use of the antennae. 
Of late years no new facts have come to light. Robineau Desvoidy alone 
(Ann. Soc. Ent. Fr. xi. p. 23), wonders that there is still doubt on this 
point. “ He has already shown, in the year 1827, that, in the crabs, as 
the outer antennae are evidently the seat of the sense of hearing, so the 
inner ones are the seat of that of smelling ; and afterwards proved, in 
his Recherches sur ^Organization Vertebrate des Crustaces, Arachnides 
et Insectes, 1828, that, in the Isopodes, the sense of hearing is no longer 
doubtful ; in the Arachnides it is wanting, while, on the other hand, the 
parts pointed out as mandibles, are here organs of smelling, and the 
poison canal in them corresponds to the lachrymal passage of the higher 
animals. In the insects, the antennae are organs of smelling, and usually 
also of touch. They have no organ of hearing at all.” 
INSECTA. 
Partial essays on this class have been laid before the Pari- 
sian Academy, by Percheron (Compt. Rend. d. Seanc. de 
I’Acad. de Sc. xiii. n. 24, and in Froriep Neue Notizen, xxi. 
p. 49), and by Bridle (Ann. d. Sc. Nat. xvii. p. 257). 
Neither of these will be of any benefit to science, as they are not 
grounded on new researches on the difierent orders. 
Percheron takes the parts of the mouth as characteristics of the first 
rank, and divides insects into Chewing {Neuroptera, Orthoptera, and 
Coleoptera), Chewing and Sucking (Hymenoptera), and Sucking (Hemip- 
tera, Biptera, Lepidoptera). But where are the Strepsiptera, which can 
neither chew nor suck, and also all the wingless orders ? 
197 
