414 Miscellaneous. 
ectoderm lying in the median longitudinal axis, from which, 
according to Sarasin, the pedal, intestinal, and visceral ganglia pro- 
ceed, and which he homologizes with the ventral nerve-cord of the 
Annelids. 
In opposition to Sarasin I must lay stress upon the following 
points. There is in Bythinia a separate mesoderm, which arises 
from the endoderm, and the development of which from the two 
primitive cells is traceable step by step. The archenteron proceeds 
from an invagination of the endoderm. The whole mid-gut, 7. ¢. 
stomach and liver, as well as end-gut (if we can use the term at all 
as applied to mollusks), arises from the archenteron, which always 
exhibits a distinct lumen. The mouth proceeds directly from the 
blastopore, accompanied by an invagination of the ectoderm, which 
forms the cesophagus ; consequently a complete closure of the blas- 
topore does not take place. The anal opening corresponds to a small 
pit at the hinder end of the blastoporal groove. Primitive kidney 
and kidney, apart from their ectodermic excretory ducts, are of 
mesodermic origin ; the same is true for the heart and pericardium. 
The ganglia arise completely separate from one another, and do not 
come into connexion until afterwards.—Zoologischer Anzeiyer, 
xiv. Jahrg., 1891, no. 376, pp. 885-388. 
On certain Reproductive Phenomena in Cirrhipedes. 
By M. A. Gruvet. 
The history of the preliminary phenomena of fertilization in the 
Cirrhipedes is little known. Darwin, relying on the anatomical 
characters (length of the penis) and on the observation that the ova 
are not ripe at the same time as the spermatozoa, concluded that 
reciprocal fertilization must take place, but never actually witnessed 
it. I was fortunate enough, during my stay at the seaside*, to 
make a few interesting observations on this subject. 
IT had in a tank of the aquarium several specimens of Balanus (B. 
tintinnabulum) which had been living for some time and were adult ; 
my attention was attracted by the very peculiar movements of one 
of them. 
The movements of the cirri were accelerated, then all at once the 
latter stopped, opened behind, and from the midst of them there 
arose a sort of very mobile tentacle, which was moved to the right, 
to the left, backwards, and in every direction, as if seeking for 
something: this was the penis. Soon a contraction set in and 
emission took place; the penis then resumed its position between 
the cirri, which also resumed their ordinary movements, until the 
occurrence of a fresh series of similar phenomena. 
My attention once directed to this point, I was not long in dis- 
covering analogous phenomena in Lepas anatifera. 
Individuals of the latter species embrace one another to a certain 
extent with their cirri. It frequently happens that the fertilized 
* These investigations were carried out at M. de Lacaze-Duthiers’ 
laboratory of experimental zoology at Roscoff during the months of 
August and September, 1891, 
