ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
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tion the cells, which were called by Frenzel the fermentative cells, 
become coloured ; some time after injection these cells have been found 
in the gastric juices and in the intestine. Some colouring matters intro- 
duced into the intestine do, and others do not, pass through the intestine. 
If a crayfish be examined immediately after an injection has been made 
into the anus, it will be found that the colour has penetrated into the 
tubes of the pancreas. Carmine and indigo-carmine are not absorbed by 
the cells, but become massed in the form of granules, and these granules 
are enveloped by a delicate membrane. Methyl-blue is absorbed in 
considerable quantity by the cells, but the author thinks that it does not 
penetrate into the body of the animal. He has attempted to put the 
tubes of the pancreas into physiological salt solution with methyl-blue, 
but he never obtained the same kind of coloration as in the living Cray- 
fish ; this coloration may be shown to depend on the vital activity 
of the cells. If a crayfish in which methyl-blue has been injected be 
left untouched the colour disappears after death, and the pancreas 
becomes brown. On examination, however, the surface of the organs 
becomes, after some time, blue, on account of the oxidation produced by 
the oxygen of the air. 
The author has made some experiments with peptones, and he is led 
to the conclusion that, if the pancreas is a digestive gland, it has also an 
excretory and perhaps an absorbent function. At any rate, digested 
food passes into its tubes, and it is not possible to prove that absorption 
takes place in the intestine. 
Hippa emerita.* — Dr. B. Sharp explains the mistake some writers 
have made in saying that this animal burrows head forwards, by ex- 
plaining that the posterior pair of thoracic feet are bent upwards over 
the posterior part of the carapace, and resemble, on superficial observa- 
tion, antennae. For this reason the posterior part of the body has been 
taken for the anterior. The posterior feet of this crustacean are em- 
ployed in loosening the sand, while the other limbs push the animal 
backward into it ; this mode of progression is more or less common to 
all Decapods. To preserve the colours of the animal Dr. Sharp recom- 
mends that they be placed, while yet alive, in a 50 per cent, solution of 
corrosive sublimate, and left in it for two days ; after this they should 
be washed in pure water and dried. 
Development of Germ-stripe of Mysis.f — Dr. B. S. Bergh finds that 
the cells of the transverse stripe which appears early in the blastoderm 
of Mysis soon become (1) wandering vitellophages, (2) elements of the 
enteric endoderm, or (3) primitive cells of the muscle-plates (mesoderm 
of authors). As soon as four of these last have appeared on either side 
they commence to give rise by budding to smaller cells ; as growth goes 
on, the muscle-plates become distinctly segmented, and the author does 
not doubt but that the segments into which they fall are primitive seg- 
ments. The muscle-plates do not form a continuous layer until these 
segments fuse with one another. 
The ingrowth which gives rise to the deeper cell-layers corresponds 
to the gastrular invagination, but it cannot be definitely asserted whether 
* Proc. Acad. Nat. Sci. Philad., 1892, pp. 327-8. 
t Zool. Anzeig., xv. (1892) pp. 436-40. 
