ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 637 



artificial cultivations (albuminous solutions, &o.) exhibits manifold 

 variations of form, and often produces numerous mobile processes. 



II. Hsematozoa of Lizards. Within the red blood-corpuscles of 

 Lacerta viridis three different forms were distinguished: (1) a quiescent 

 worm-like cytozoon, resembling Hsemogregarina Step, lying near the 

 nucleus of degenerating corpuscles ; (2) a smaller mobile form, within 

 almost normal hsemocytes, and characterized by a number of strongly 

 refracting round granules at each end of the otherwise clear worm- 

 like body ; (3) a larger form, with one end distinctly thicker, occur- 

 ring free in the blood as well as within the corpuscles. These 

 varieties are connected by intermediate forms, and the differences 

 probably depend on age and nutritive conditions. 



III. Hsematozoa of Birds. (1) A form resembling Hsemogre- 

 garina, about the length of a red blood-corpuscle, with a screw-like 

 motion, usually with one end rounded and the other more pointed, 

 and exhibiting a vesicular nucleus within the blueish-grey, homo- 

 geneous strongly refracting body, was observed swimming free in the 

 plasma. (2) A second, much longer form very closely resembled 

 Trypanosoma fusiforme piscium. (3) A third Hasmatozoon occurs 

 frequently within the red blood-corpuscles as a " pseudovacuole " of 

 variable shape, which increases in size, assumes a spherical form, and 

 causes the disintegration of the haemocytes. It eventually liberates 

 itself, and is seen rotating rapidly in the plasma by means of its 

 flagellum. 



. BOTANY. 



A. GENERAL, including- the Anatomy and Physiology 

 of the Phanerogamia. 



o. Anatomy.* 



Plasmolytic Studies of the Membrane of Vacuoles-j — Dr. H. 

 de Vries has made a large number of observations on the nature of 

 the membrane — for which he proposes the term tonoplast — which 

 separates a vacuole from the surrounding protoplasm. Coincident 

 results were obtained from a large number of plants, the one best 

 adapted for the purpose being Spirogyra nitida. The following is a 

 summary of the more important. 



It is universally the case in the vegetable kingdom, and in the 

 most various forms of tissue, that the vacuoles possess a true mem- 

 brane, which may readily be made visible by the application of 

 a 10 per cent, solution of potassium nitrate with the assistance of 

 eosin ; the tonoplast being more resistent to the action of this reagent 



* This subdivision contains (1) Cell-structure and Frotoplasm (including the 

 Nucleus and Cell-division ; (2) Other Cell-contents (including the Cell-sap and 

 Chlorophyll); (3) Secretions; (4) Structure of Tissues; and (5) Structure of 

 Organs. 



t Pringsheim's Jahrb. f. Wiss. Bot., xvi. (1885) pp. 465-598 (4 pis.). 



