MORPHOLOGY AND PHYSIOLOGY. Plot. 25 
of acid ill Protozoa and chiefly its r61e in digestion, in Carchesium poly- 
pinum and in the plasmodia of Mycetozoa. 
DArtog & Dixon (104) in studying the digestive ferments of Pelomyxa 
palustris have found ptyalin and pepsin. Trypsin, renniri, and steapsin 
Seeni to be absent. 
Labb]£ (137) describes another case of the co-existence of a mono- 
sporous and a polysporous Coccidium in the same host. Similar cases had 
formerly given rise to the theory of dimorphism of Sporozoa. But the 
two forms in question aro quite distinct species. 
Lister (158), in treating of dimorphism in Eoraminifera , suggests that 
the megalospheric and microspheric forms may be members of a recurr- 
ing cycle of generations. 
Sacharoff (22l) has made experiments on the influence of cold on 
malaria parasites, arid finds that they can tetairt their vitality even if 
exposed to a freezing temperature for a week. 
Schewiakoff (232) has studied the movements of Gregarines, chiefly 
on Clepsidrina munieri. He finds that the same are not active, but caused 
by the formation of gelatinous threads. These threads harden, form a 
stiff stalk, which becomes fixed at its free end to the supporting object, 
and the animal is pushed along by the excretion of fresh gelatinous 
substance. 
• Ryder (216) has studied the growth of Euglena viridis , when con- 
strained principally to two dimensions of space, and applies his results to 
the development of the blastoderm, which is subjected to a similar 
restraint. 
Wildeman (267) has made experiments on the influence of heat on 
Euglena. 
4 Methods op Preservation and Preparation. 
MAGGi (161) giveS rdetliods for the staining of Protozoa. 
; RIiOMbLER (197) describes a, metliod of double staining in order to 
distinguish between living substances and dead Or inofganic ones after 
their preservation. 
Rosin (207) describes how living parasites of malaria are to be treated 
by quinine and methyl blue. 
Ryder (217) describes a useful method of entrapping, killing, embed- 
ding, and orienting Infusoria for the microtome. 
Sforza (239) has discovered a simple process for staining the Hamato- 
zoa of malaria. 
