ii6 PROTOPLASM 



well-dried plasmodia be brought for twelve to twenty-four hours 

 into olive oil, and then the oil be washed off carefully with hot 

 water, the investigation of such preparations in water teaches us 

 that the alveoli of the protoplasm are filled, in many places at 

 least, with oil. The preparations become still more instructive if, 

 after the oil is washed off, they are placed for some time in 1 per 

 cent osmic acid, which turns the oil brown. That the oil actually 

 fills the alveoli of the protoplasmic framework in many places 

 can be made out very plainly in thin portions, since the contents 

 of the alveoli now show a considerably stronger power of 

 refraction than the framework, whilst before the reverse was the 

 case. With a rather higher focus the contents of the alveoli 

 that are filled with oil now appear very clear and bright, while 

 the framework becomes very dark, and hence much sharper and 

 more distinct than in places not filled with oil. As the tube of 

 the microscope is raised the stronger refraction of the contents 

 of the alveoli can be definitely established, since during the 

 process the contents of each one becomes a diminishing, glitter- 

 ing point, while the less refractile framework becomes darker. 

 I possess a photograph of the alveolar framework filled with oil 

 which shows this exceedingly well. The faint framework can 

 also be recognised with sufficient distinctness in the neighbouring 

 parts that are not filled with oil, and in this way it is still more 

 definitely shown that here is really a case of ths alveoli being filled 

 with oil. 



As has been remarked, I hold these results to be especially 

 important, since they markedly support my view, that the 

 alveolar contents are a watery solution. For if in dried or fixed 

 protoplasm the contents can be replaced by oil, the conclusion 

 is incontestable, and refutes more particularly the view of 

 Schwarz, discussed below on p. 205, who explains the contents 

 of the alveoli as being identical with the substance of the frame- 

 work, only rather less refractile. 



Pelomyxa palustris, Greeff 



By the kind help of my respected friend and colleague 

 Blochmann, I obtained during the past winter a considerable 

 quantity of this highly interesting Rhizopod from Rostock. I 

 made use of the opportunity to study the nature of the proto- 

 plasm, in addition to other observations. I must state, to begin 

 with, that Pelomyxa, as I have already pointed out before 

 (Protozoa, p. 99), in the normal condition possesses no cortical 

 protoplasm or ectoplasm. At times hyaline portions, usually of 



