ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
195 
By mixing with the food various anilin colours or fat, the author has 
been able to assure himself that there exist two absorbing organs ; the 
liver, especially at the extremities of its cseca, absorbs soluble bodies, 
such as peptones and sugars, while the short mid-gut absorbs fatty 
bodies, which are taken in by the cells in the form of fine droplets, and 
the whole phenomenon is very similar to the absorption of fat by the cells 
of the small intestine of Vertebrates. 
The “liver” of Decapod Crustacea, besides secreting digestive 
ferments and accumulating reserve products, plays an important part 
in absorbing the soluble products of digestion, and in regulating the 
amount of water in the blood. 
Correlated Variations in Carcinns Msenas. * — Prof. W. F. R. 
Weldon has studied the variations of eleven individual parts in a set 
of 1000 adult females of the shore crab at Plymouth and Naples re- 
spectively. The principle which is animating him in the laborious 
investigation he has undertaken may be gathered from the following 
passage : “ It cannot be too strongly urged that the problem of animal 
evolution is essentially a statistical problem : that before we can properly 
estimate the changes at present going on in a race or species we must 
know accurately (a) the percentage of animals which exhibit a given 
amount of abnormality with regard to a particular character; (b) the 
degrees of abnormality of other organs which accompanies a given ab- 
normality of one ; (c) the difference between the death-rate per cent, in 
animals of different degrees of abnormality with respect to any organ ; 
( d ) the abnormality of offspring in terms of the abnormality of parents, 
and vice versa. These are all questions of arithmetic ; and when we know 
the numerical answers to these questions for a number of species, we 
shall know the direction and the rate of change in these species^at the 
present day, a knowledge which is the only legitimate basis for specula- 
tions as to their past history and future fate.” 
Crayfish with Abnormal Appendages.|— Dr. A. Dendy has found 
a specimen of the Australian Crayfish ( Astacojpsis bicarinatus ), which 
agrees very closely with the European form as regards the thoracic 
appendages, with small exopodites on three of the ambulatory appen- 
dages. He regards their presence as an additional proof of the generally 
accepted view as to the derivation of the ambulatory appendages from a 
primitive biramose type. 
Shifting of the Germinal Streak in Gammarus.?— Dr. R. S. Bergh 
points out that the germinal streak of Gammarus pulex undergoes 
in its early stages a very remarkable displacement. At first it extends 
transversely across the oval egg, afterwards it lies obliquely, and finally 
it assumes its definite position with its median plane in the longitudinal 
axis of the ovum. The dorsal organ is from the first in the middle of 
the back, and it remains there unmoved. Its unpaired origin in Gam- 
marus must be homologous with its paired origin in Mysis ; there has 
been either fusion or splitting. The cell-divisions in the anterior and 
middle portion of the germinal streak of Gammarus show the same 
* Proc. Roy. Soc., liv. (1894) pp. 318-29. 
f Proc. Roy. Soc. Victoria, 1893, pp. 160 and 1. 
% Zool. Jahrb. (Abth. Anat. Ontog.), vii, (1893) pp. 235-48 (1 pi.). 
