-i- Olive. Mitotie division of tlie nuclei of the Cyanophyceae. 
Fig. 33. Two vaeuolar formations are seen in tlie central body. It is 
possible tliat tbese are slime glöbules. Tlie acliromatin is bere more dis- 
tinctly visible than in fig. 32. 
Fig. 34. A longitudinal section of a filament, still lying in tbe tliick. 
gelatinons membrane. Tlie lowermost nnclens is completely divided: but tlie 
central spindle may still be dimly seen. Tlie mantle fibers in tlie latter cell 
are more sbarply detined. 
Fig. 35. Gloeocapsa, left abont two days in cliloroform water, Kothing 
appears to reniain in tlie dead. colorless cells but tlie colorless cyanopbycin 
granules. 
Fig. 36. Gloeocapsa, left 24 liours in cliloroform water. Some of tbe 
extracted pbycocyanin may be seen in tbe space between tbe cell and tbe 
gelatinous wall. Tbe cells so treated are usually brigbt green: sometimes 
yellowisli. Tbe granulation is very distinct; obviously tbe granules are 
tbe sanie as tbose in fig. 35. 
Plate II. 
(Figs. 37—53, Calothrix Giermalis IIansgirg.) 
Fig. 37. Section of tbe large end of a filament, in its gelatinous envelope. 
sbowing tbe lieterocyst witb disorganized nucleus, and tbree vegeta¬ 
tive cells, eacb witli a nucleus in division. In tbe lowermost cell, 
division is completed. In tbe otber cells, tbe stain is not differentiated 
sufficiently to sliow clearly cliromosomes and central spindle. Mantle 
fibers are dimly sliown. Tbe ring formed walls are not. in tliis in- 
stance, well stained by tbe Heid. 
Fig. 38. A preparation stained ' witb Flem., sbowing dimly tbe central 
body. Tbe cavities in wbich tbe cyanopbycin granules lie are bere 
seen to surround completely tbe nuclear body. 
Fig. 39. Tbree cells near tbe attenuated end of tbe filament. Tbe central 
body, poorly stained witb Flem., is bere greatly elongated. 
Fig. 40. A similar section, stained witb Heid. "'Cavities containing cyano¬ 
pbycin are sliown in tbe cytoplasm. 
Fig. 41. A broad, vegetative cell, stained witb Heid. Tbe acbromatic. as 
well as tbe cbromatic, structures are sbown. 
Fig. 42. Cross section of a large vegetative cell in wliicli cliromatin gra¬ 
nules and linin appear somewbat fused togetber. Flem. 
Fig. 43. A cross section in wbicli 16 cliromatin granules are seen. Heid. 
Fig. 44. A cross section, stained witb Flem. At one side of tbe central 
body is a slime globule. Many unstained cyanopbycin granules are 
sbown in tbe cytoplasm. 
Fig. 45. A similar preparation to tliat in fig. 44. 
Fig. 46. A cross section of an elongated cell. Flem. 
Fig. 47. An elongated cell strongly stained witb Heid. 
Fig. 48. A preparation stained witb Flem., in wbicb only cyanopbycin 
granules are stained red witb safranin. 
Fig. 49. A lieterocyst in longitudinal view, stained witb Heid. Tbe dark 
_ body in tbe middle is probably a „Verschlußkörper“ (Ko bl). 
Fig. 50. Cross section of a lieterocyst, showing in tbe middle tbe „Yer- 
sclilußkörper“, and surrounding it what appears to be a nuclear 
vacuole, bounded externally witb a ring of disorganized chromatin. 
Fig. 51. A similar preparation, with central vacuole. 
Fig. 52. A young lieterocyst in cross section; tbe gelatinous slieatli is also 
sbown. 
Fig. 53. A young lieterocyst in cross section; sbowing a dim acbromatic 
reticulum in tbe nuclear cavity. 
(Figs. 54—60, Nostoc commune Vauclier.) 
Fig. 54. A preparation stained witb Heid. Tbe central body not well 
differentiated. 
Fig. 55. A similar preparation, sbowing about 8 chromatin granules. Botli 
slime globule.s and cyanopbycin granules are sbown. 
