PLATE 10. Confervoidese. Crystals. 



Figure 



1. Cosmarium margaritiferum, Turp. ; conjugating pair with imperfect sporange. 



2. Cosmarium botrytis, Bory ; conjugating pair with sporange, enveloped in jelly. 



3 A. Closteriwn acerosum, Schrank. a, b, c, different stages of conjugation ; 

 d, frustules apparently produced from a sporange. 



3 B. Closterium lunula, Miill. ; the contents converted into globular bodies. 

 4. Fragilaria penicillata, Lyngb. a and b, successive stages of conjugation. 



5 A. Surirella bifrons, Ehr. ; conjugating pair, with intermediate large sporangial 



frustule. 

 5 B. Surirella bifrons, Ehr., with the contents converted into globular bodies. 



6. Epithemia turgida, Ehr. a, b, c, d, e, successive stages of conjugation producing 



pairs of sporangial frustules. 



7. Meloslra (Aulacosira) crenulata, Thw. , filament with two conjugating pairs 



of cells and perfect sporangial frustules ; 6 and c, large filaments produced 

 by sporangial frustules. 



8. Melosira varians, Ag. a, small filament producing sporangial frustules by con- 



jugation ; 6, large filament developed from sporangial frustules. 



9. Orthosira Didciei, Thw. Successive stages of production of sporangial frustules 



after conjugation. 



10. Pinnularia viridis, Sm., with the contents converted into globular bodies. 



11. Pediastrum granulatum, Ktz. , a frond with most of the cells empty, three 



full, and the contents of another swarming out as zoospores ; b, c, d, swarm of 

 zoospores producing a new frond. 



12. Crystals of sugar of milk. 



13. diabetic sugar. 



14. indigo, sublimed. 



15. oxalate of soda. 



16. sulphate of lime. 



17. phosphate of lime. 



18. sulphate of strontia. 



19. nitrate of soda. 



20. allantoin. 



21. antimoniate of soda. 



22. protoxide of antimony. 



23. butyrate of baryta, a, rapidly, b, slowly formed. 



24. hydrofluosilicate of baryta. 



25. sulphate of baryta, a, precipitated from concentrated, 6, from very 



dilute solution. 



26. carbonate of potash. 



