Cuap. XVIII. ABSORPTION. 437 
also a yellow chitinous head of some animal with an internal 
fork, to which the cesophagus was suspended, but I could see 
no mandibles; also the double hook of the tarsus of some 
animal; also an elongated greatly decayed animal; and lastly, 
a curious flask-shaped organism, having the walls formed of 
rounded cells. Professor Claus has looked at this latter organism, 
and thinks that it is the shell of a rhizopod, probably one of the 
Arcellide. In this bladder, as well as in several others, there 
were some unicellular Algz, and one multicellular Alga, which 
no doubt had lived as intruders. 
A second bladder contained an Acarus much less decayed 
than the former one, with its eight legs preserved; as well as 
remnants of several other articulate animals. A third bladder 
contained the end of the abdomen with the two hinder limbs 
of an Acarus, as I believe. A fourth contained remnants of a 
distinctly articulated bristly animal, and of several other organ- 
isms, as well as much dark brown organic matter, the nature 
of which could not be made out. 
Some bladders from a plant, which had lived as an epiphyte 
in Trinidad, in the West Indies, were next examined, but not 
so carefully as the others; nor had they been soaked long 
enough. Four of them contained much brown, translucent; 
granular matter, apparently organic, but with no distinguish- 
able parts. The quadrifids in two were brownish, with their 
contents granular; and it was evident that they had absorbed 
matter. In a fifth bladder there was a flask-shaped organism, 
like that above mentioned. A sixth contained a very long, 
much decayed, worm-shaped animal. Lastly, a seventh bladder 
contained an organism, but of what nature could not be dis- 
tinguished. - ; 
Only one experiment was tried on the quadrifid pro- 
cesses and -glands with reference to their power of 
absorption. A bladder was punctured and left for 
24 hrs. in a solution of one part of urea to 437 of 
water, and the quadrifid and bifid processes were found 
much affected. In some arms there was only a single 
symmetrical globular mass, larger than the proper 
wucleus, and consisting of yellowish matter, generally 
translucent but sometimes granular; in others there 
were two masses of different sizes, one large and the 
