300 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
origin of the blood-cells in Lepidoptera and Diptera, and this may be 
the case here. But it seems to Faussek more likely that the “ white 
body ” is a “ substitution-organ ” whose original ectoderm is replaced 
by mesoderm, as in the thymus of Vertebrates. 
y. Gastropoda. 
Anatomy of Mollusca.* — Dr. L. Plate continues his account of the 
Mollusca he found on the coast of Chile. Crepidula adolphei is extra- 
ordinarily common in the Bay of Talchuano, where it exists in two 
varieties. If we take adult examples of these two forms, we should cer- 
tainly- regard them as representatives of two distinct species, but the 
young forms and half-grown animals present so many intermediate 
stages that it is quite impossible to separate them. We appear to have 
to do here with two varieties which have adapted themselves to different 
modes of life. The one which is most exposed to light develops a 
quantity of pigment. The details do not allow of an abstract. 
The renal organ of Chiton granosus is also described. 
In his eleventh note an account is given of Chilina dombeyana .f As 
most of the species of this genus are remarkably small, Dr. Plate was 
lucky in finding the above-named species, which is about half the size of 
the common pond snail of Germany. He finds that its respiratory cleft 
is not contractile ; the mantle cavity has no special vascular network 
which functions exclusively as a lung. All the venous blood that passes 
into the mantle goes through a network formed by the renal walls, so 
that the kidney is also a respiratory organ. The radula is rudimentary; 
the stomach consists of several portions ; the heart lies far forward, near 
the left anterior angle of the mantle cavity. The division into the 
vas deferens and oviduct occurs some distance from the hermaphrodite 
duct. For some distance both efferent ducts are united to form a sperm- 
oviduct. The penis is dentated, and there are calcareous secretions in 
the vagina. All the ganglia are very well developed. The commissures 
are very long. The kidney opens directly, without a ureter, into the 
mantle cavity. 
Myology of some Pulmonate Mollusca.f — Mr. W. E. Collinge has a 
note on the myology of some pulmonate Mollusca, considered as a dis- 
tinctive feature in the discrimination of genera, &c. At the outset of 
his investigations he finds, what nearly all workers in other groups have 
noticed, that the muscles which do not supply either sense or other 
important organs are subject to great variation in form, size, and position. 
His investigations further resolve themselves into a comparatively simple 
series of observations on three muscles : — (1) the buccal retractor ; 
(2) the tentacular retractor ; (3) the genital retractor. He has examined 
these in Avion, Limax , and Helix aspersa , and summarises his results as 
follows : — No variation whatever was found in the form, number, or 
position of the buccal retractor muscles. The tentacular retractor muscles 
are quite as constant, very slight variations only being found in the 
labial branches. Innumerable variations were found in the genital 
retractor muscles of the three genera mentioned, as well as of Testacella 
* SB. Akad. Wiss. Berlin, 1894, pp. 1071-83. f Tom. cit., pp. 1267-76. 
X Proc. Malacol. Soc., i. (1894) pp. 52-4. 
