PLATE IV 



Fig. 1. Membrane-like expansion, with a very distinct structure, from the 

 pseudopodial network of a Milliolid. Living. 



Fig. 2. Similar expansion from the richly developed pseudopodial network 

 of a Discorbina, which was killed rapidly by being placed in the vapour 

 of heated osmic acid and then stained with Delafield's hsematoxylin. The 

 drawing was made as true to nature as possible, without being schema- 

 tised in the least. 



Fig. 3. Marginal portion of a fresh-water Amoeba, which was not determined 

 with certainty, but was probably referable to Amoeba (Cochliopodium) 

 actinophora, although the envelope was not distinct. At the broader 

 end the alveolar protoplasm becomes very beautifully radially striated. 

 A more precise determination of this form was impossible, since it was 

 only observed in a fixed preparation. Picro-sulphuric-osmic acid, damar. 



Fig. 4. Amosba actinophora Auerbach (probably more correctly referred to 

 Cochliopodium, H. and L.) Picro-sulphuric-osmic acid, damar. Only a 

 portion of the margin, with the radially striated envelope (h), repre- 

 sented. Beneath this the distinctly alveolar protoplasm, of which the 

 most external layer immediately under the envelope has developed into 

 an alveolar layer (ah), o, the alveolar protoplasm in surface view, n, the 

 nucleus, with a very large nucleolus of a honeycombed structure, and a 

 framework arranged radially to the membrane. 



Fig. 5. Small living Vorticella sp. from the Mediterranean. A small portion 

 of the edge in the region of the contractile vacuole in optical section. 

 p, pellicula ; alv,^ alveolar layer ; beneath that the distinctly alveolar 

 protoplasm, in which the most external layer of alveoli is directed radially 

 to the alveolar layer. At the same time, a similar arrangement of the 

 alveoli at the surface of the large vacuole (v), which was probably the con- 

 tractile vacuole, is very distinct. Numerous strongly refracting granules 

 in the endoplasm. 



Fig. 6. Surface view of a small portion of the cortical protoplasm of Para- 

 mcecium bursaria Ehb. sp. with numerous zoochlorellos (z). Picro- 

 sulphuric-osmic acid, damar. The vertical position of the very distinct 

 alveoli of the cortical protoplasm, with regaro^ to the zoochlorellcc, is very 

 striking. 



Fig. 7. Stylonychiapustulata'Eh'b. Small portion of the alveolar endoplasm 

 with corpuscles, strongly stained with eosin, lodged in it. 



Fig. 8, a-b. Paramcecium caudatum Ehb. Killed with iodine - alcohol ; 

 then very strongly stained in Delafield's hsematoxylin, and transferred 

 to oil of cloves, and there broken up. 8, a, small fragment of the 

 macronucleus, showing beautifully the alveolar structure, and the fact that 

 the small chromatin granules, stained red, are lodged in the nodal points. 

 8, b, small fragment of the endoplasm with the larger, eosinophilous gran- 

 ules in the nodal points of the alveoli ; the latter stain slightly reddish 

 in hsematoxylin. 



Fig. 9. Two living strands of protoplasm from the hair cells of a Malva sp. ; 

 in the strand on the left the streaming has stopped, for which reason 

 the structure here appears irregularly alveolar ; in the neighbouring 

 strand, on the other hand, which is in a state of streaming movement, 

 it appears distinctly fibrillar. 



