852 NOTES, 



mother and return to her again, up to twenty-eight days, when they 

 become independent. 



In a note appended to M. Chantran's paper, M. Eobin states, that " the 

 young are suspended to the abdomen of the mother by the intermediation 

 of a chitinous hyaline filament, which extends from a point of the 

 internal surface of the shell of the egg as far as the four most in- 

 ternal filaments of each of the lobes of the median membranous plate 

 of the caudal appendage. The filaments exist when the embryos have 

 not yet attained three-fourths of their development." Is this a larval 

 coat ? Rathke does not mentiqji it and I have seen nothing of it in 

 those recently hatched young which I have had the opportunity of 

 examining. 



Note VIL, Chapter II., p. 64. 



THE "SALIVARY" GLANDS AND THE SO-CALLED "LIVER" OF 



THE CRAYFISH. 



Braun (Arbeiten aus dem Zoologisch-Zootomischen Institut in 

 Wiirzburg, Bd. II. and III.) has described " salivary " glands in the 

 walls of the oesophagus, in the metastoma, and in the first pair of maxillie 

 of the crayfish. 



Hoppe-Seyler (Pflugers Archiv, Bd. XIV. 1877) finds that the yellow 

 fluid ordinarily found in the stomachs of crayfishes always contains pep- 

 tone. It dissolves fibrin readily, without swelling it up, at ordinary tem- 

 peratures ; more quickly at 40° Centigrade. The action is delayed by even 

 a trace of hydrochloric acid, and is stopped by the addition of a few drops 

 of water containing 0.2 per cent, of that acid. By adding alcohol to the 

 yellow fluid, a precipitate is obtained, which is soluble in water and in 

 glycerine. The aqueous solution of the precipitate has a strong digestive 

 action on fibrin, which is arrested by acidulation with hydrochloric acid. 

 These reactions show that the fluid is very similar to, if not identical 

 with, the pancreatic fluid of vertebrates. 



The secretion of the " liver " taken directly from that gland, has a 

 more strongly acid reaction than the fluid in the stomach, but has 

 similar digestive properties. So has an aqueous extract of the gland, 

 and a watery solution of the alcoholic precipitate. The aqueous extract 

 also possesses a strong diastatic action on starch, and breaks up olive oil. 

 There is no more glycogen in the " liver " than is to be found in other 

 organs, and no constituents of true bile are to be met with. 



