VAN HENSEN’S HYPOTHESIS OF SPONTANEOUS GENERATION. 299 
so that, in accordance with the usual practice of zoologists, the 
species must bear the trivial name of ‘‘ tvidens,” Fab., and White’s 
name become a synonym. 
FPlatyomida binodis, White.—This is a species very closely allied 
to Empeotes ovispatus, Pasc. 
Otrorhynchus griseus, White.—This isa species unknown to me ot 
the genus Catoptes. 
Hoplocneme cinnamomea, White.—This is a species of Eugnomus. 
Hoplocneme hookeri, WWhite.—There is no specimen with this name 
inthe British Museum collection; but there is a type labelled H. 
vufipes, \White, and I have no doubt that this is meant for H. hookent, 
the latter name having probably been substituted after the original 
description had been drawn up; at any rate the ‘“ H. vufipes”’ is the 
insect common in New Zealand we call H. hookem, which name it 
will, of course, continue to bear. 
Lyctus depressiusculus, White.—This is one of the commoner of the 
species of Pycnomerus; but not having suspected such a thing I had 
no specimens of the latter genus to compare with it. 
Ptenus sutuvalis, White.—This is the insect I described under the 
name of Atopida broum. ‘The type is pinned, and the wing-cases 
are gaping, so that the colour of the suture looks different from 
usual. As White’s description is too brief and inexact to charac- 
terise the species which he reterred, without a word of remark, to 
an erroneous family, I think it would be unnecessary to adopt the 
name he proposed His mistake is quite unpardonable, as in this 
same work he found the genus Atofida for another species con- 
generic with this insect, which he places in Ptevicus—a well-known 
genus of another family—without any comment. 
Ptenus pilosus, White.—This is a small insect of a genus in the 
Anobiade ; but the type is in such a dirty state that it cannot be 
identified till it has been cleaned. Ptenus murinus and Anobium tri- 
costellum are not inthe British Museum collection. 
VAN HENSEN’S HYPOTHESIS OF SPONTANEOUS 
GENERATION. 
<>— 
BY DR. R.. VON LENDENFELD, SYDNEY. 
> 
Van Hensen* published a most ingenious hypothesis concerning 
this question, which, although it does not appear to hold good for 
the purpose of explaining the postulated ‘* Unzeugung,” still serves, 
as I think, to explain the vital phenomena in a manner equally 
clear and comprehensible. 
Besides tat granules and water, protoplasmic cells contain a 
spongy network of threads which consist of strings of molecules. 
Herein protoplasm resembles boiled starch or gum (Nagell). 
There appear to be two such networks interlaced, consisting of two 
different kinds of protoplasm. The one kind imbibes carmin very 
freely—Chvromatin; the other can not be coloured so easily— 
* Handbuch der Physiologie, Band VI, Van Hensen, Physiologie der Zeugung, 
Seite 147-148, 
