636 General Notes. ` [June, 
pores; that of digestion in lipogastry is taken up by the ciliated 
chambers, or possibly by the ectoderm and mesoderm. The dis 
covery of digestive ferments (pepsin, trypsin) in the body of the 
sponge has its importance somewhat reduced by the uncertainty 
which prevails as to the exact distribution of these compounds ia 
the living animal. A reserve of nutriment occurs at certain times 
in several widely distinct sponges, and in some cases starch has 
been demonstrated between the cells, but there appears reason to 
regard this as derived from alge. Oily matters have been ex- 
tracted by chemical processes from sundry sponges, and traces of 
fatty matter have been observed. Though so commonly found 
dissolved in fatty matters in vertebrata, coloring matters are found 
abundantly in the sponges, although fats are so scanty in these 
organisms. They occur in the endodermal ciliated cells ( Spongelis 
avara, Calcisponges) or in the mesoderm ( Euspongia officinals, 
Chondrosa). Some forms (Calcarea), from being colorless, take 
a brown color when placed in spirit; others (Suberites, Hirciaia, 
and Stelletta, spp.) lose their color if exposed to the light. 4, 
sina aerophoba offers a remarkable example of change of blue. 
consequent on death, viz., from a sulphur-yellow to Prussian 
This is caused by changes in certain roundish, refar 
dermal cells, with bladder-like nucleus, and small -a a 
granular space. The color is preserved unchanged in , 
salicylic acid. -The substance which produces it 1s cons! 
be reserve nutriment. The same body (aplysinofulvin) ape 
to occur in Aplysilla sp. and Hircinia sp., but changes ™ ii 
Š j: 5 i # : because the 
rapidly in Aplysilla than in Aplysina, perhaps pe 
ducing ferment which hinders its conversion is decom paes 
slowly in the latter case. The horny fibers have eo have yet 
elathrus would seem to suggest. In connection m! n that, @ 
of sponges, it is remarked that Cavolin’s obs the old parts. 
having taken root, the pieces of sponge shed over 
mucilaginous mass, in which the skeleton appr The youngest 
might be utilized as giving a hint where were the study a ; 
parts, when these are sought after, and thus turta coget, DE 
tissue-development.—/ournal of Royal Murosco, g 
cember, 1883. 
the 
4 inks that 
Pepat GLanps oF MorLusca.—j]. Carriere thin hs are the 4 
amellibrane kee 
to De * 
orifices of various glands ; water does ne: by de kidney; 1%" 
blood alone can bring that about. 
the means for introducing water int 
