ILLUSTRATIONS. 



Page. 

 Plate I. Rhizopus nigricans. Fig. 1. — Group of sporangiophores with sporangia. 

 Fig. 2. — Longitudinal section of young stolon. Fig. 3. — Longitudi- 

 nal section of old stolon. Fig. 4.— Disintegrating nuclei from old 

 stolon. Fig. 5. — Longitudinal section of young sporangium. Fig. 



6.— Longitudinal section of nearly full-sized sporangium 40 



II. Rhizopus nigricans. Fig. 7.— Longitudinal section of full-sized spor- 

 angium before the columella is formed. Fig. 8.— Longitudinal sec- 

 tion of sporangium in which the columella is l)eing formed. Fig. 

 9.. -Section of small part of sporangium showing cleavage furrows. . 40 



III. Rhizopus nigricans. Fig. 10.— Longitudinal section of sporangium 

 showing spore formation. Fig. 11.— Nuclei from columella that ha.s 

 just been formed. Fig. 12. — Sporangium in which the spores are 

 completely formed. Fig. 13.— Xuclei from columella of old spor- 

 angium. Fig. 14. — Ripe spores in their liviBg condition 40 



lY. Phycomyces nitens. Fig. 1.^.— Longitudinal section of young sporan- 

 gium. Fig. 16. — Small part of young sporangium very highly mag- 

 nified. Fig. 17.— Formation of zones in sporangium. Fig. \S.— 



Layer of vacuoles in sporangium 



Y. Phycomyces nitens. Fig. 19.— Formation of columella. Fig. 20. — 

 Structure of vacuoles an<l nuclei. Fig. 21.— Formation of the 

 spores. Fig. 22. — Furnjws cutting outward from columella cleft. 

 Fig. 23. — Furrows from the vacuoles cutting out to the periphery. 

 Fig. 24. — Section showing nearly ripe spore.«. Fig. 25. — Ripe spores 

 in their living condition. Fig. 26.— Peculiar-shaped spores. Fig. 

 27. — Yery irregular-shaped spore 40 



YI. Figures illustrating mechanics of cleavage. Fig. 2S.—Pilobolus before 

 formation of columella. Fig. 29.— PiloboJus during formation of 

 columella. Fig. 30. — Pilohohis after formation of columella. Fig. 

 31.—Pilobolus during formation of spores. Fig. 32.— Synchitriurn 

 during formation of spores. Fig. 33.— FuUgo during formation of 

 spores. Fig. 34. — Egg of squid during segmentation 40 



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