782 
Analyses of Books . 
[December, 
lav public — that the pupa condition is a kind of death which 
should entirely dissociate the past and the future career of the 
insert, is ill-founded. 
We come now to the imago condition. Here the author, with 
somewhat questionable prudence, attempts the definition of the 
illusive idea “ species.” He says Hereby the notion of 
species is established that we say of butterflies which copulate 
with each other, lay eggs, and so produce descendants of the 
same character, which again give birth to similar beings, that 
they make up a ‘ species,’ or ‘ belong to one species. H 
quotes also Piochard dela Brulerie, who defines species as the 
“ totality of beings who are capable of producing to infinity 
beings identical to themselves.” As we have not observed an 
infinite number of generations, either of butterflies or of any 
other animal, we cannot accept these definitions which l assert 
the permanence of species, and overlook the case \ 0 ^ 
which are known to occur in Nature, and are probably far from 
rare Herr Keferstein examines the various morphological cha- 
rarters by which species are distinguished,— such as size, 
antennae, palpi, feet, wings, scales, pattern, &c.,— and finds them 
all liable to flurtuate. , , • 
Entering upon the different classes of varieties and their 
causes, he enumerates sexual variation, the distinction (where, it 
exists) between the male and female of the same species , ge 
ration-varieties-cases where, e.g., the summer and winter or 
the spring and autumn brood differ; climatic and local varieties, 
of which the author enumerates many interesting instances , 
ordinary varieties, those which cannot be explained, the 
twenty-four varieties of T. parmatana which Fischer von Rosier 
Stamm obtained from a single brood of larv*. Hybrids and 
monsters he classes as aberrations. He enumerates a numb 
of variations produced by unusual diet, though his own experi- 
ments in this direction have given mere y ’^ e , . V j 
considers that the beginning of variation must be sough 
tH In ^conclusion we find a few remarks on the odours, the 
luminosity, and the stridulation of different Lepidoptera. 
We can commend this little work to entomologists as a _ trea 
sury of interesting faCts, and we feel certain that all will regret 
to learn that the author's researches are suspendedbytheseverest 
affliction which can happen to an observer of Nature— a serious 
affertion of the eyes. 
