PLATE 3.— Confervoide^. 



Figure 



1 . Chlorococcum vulgare, Grev. «, groups in natural condition ; b, an isolated cell 



showing the granular contents ; c, dividing cells treated with sulphuric acid 

 and iodine. 



2. Protococcus viridis, nob. a, groups of cells, the upper one with eight in a 



linear series; those to the right with the contents dividmg into numerous 

 gonidia (?) ; b, zoospores set free from the cells by the solution of the cellulose 

 membrane ; c, an isolated cell dividing and about to set free its contents as two 

 zoospores ; d, resting-cells with a thick coat and reddish contents ; e, a zoo- 

 spore with the ciha cast off; /, a zoospore with imperfect or retracted cilia; 

 ff, remains of a zoospore left on a glass slide for twenty-four hours. 



3. Pahnella cruenta, R. Br. a, patch of the jelly with single cells, and dividing 



and divided pairs ; b, similar cells without the gelatinous layer, the smaller 

 granules similar to those seen in the jelly of « ; c, cells treated with sulphuric 

 acid and iodine, showing the cellulose coat and granular contents ; c?, diagram 

 indicating the relative dimensions of the cells of Pcdmetla 7iivalis. 



4. Gloeocapsa 2^olydermaticay Ktz. 5. a, by Sarcina ventricidi, Goodsir. 



6. Coccochloris Brebissonii, Ktz. a, group of cells, some di\-iding within their cell- 



coat ; b, a linear group ; c, a pair of cells conjugating ; d, conjugated cells 

 encysted and passing into the resting stage. 



7. Urococcus Hookerianus, Berk. 8. «, b, Hydrurus Decluzeliij Ag. 

 9. Botrydina vulgaris, Ktz. a, 6, c, c?, successive stages of growth. 



10. Tetraspora gelatinosa, x\g. Four parent-cells producing bi-ciliated zoospores, 



imbedded in the gelatinous frond. 



11. Gonium pectorale, Miill. a, perfect frond; 6, the same seen edgewise; c, a 



single zoospore. 



12. Gonium tranqidllum, Ehr. 13. Gloeocapsa ampJa, Ktz. 



M. a, b, Volvox globatorl, forms related to Syncrypta and Eudorina of Ehrenberg. 

 15. Spirulina oscillarioides (Turp. ?). 16. Spirulina Jenneri, Ktz. 

 17. «, Bacterium termo, Duj.; 5, B. catenida, D. ; c, B. punctum, Ehr. ; c?, B. tri- 

 loculare ^Ya^ix, 18. Vibrio subtiliSyYlvc. 

 19. Vibrio rugula, Ehr, 20. Vibrio prolifer , Ehr. 



21. Vibrio bacillus, Ehr., prob. Anabaina subtilissima, Kiitz. 



22. Spiroc/icEta j^licatilis, Yihr. 23. Spirillum volutans, Yhr. 

 24-36. Volvox globator, Ij. 24< A perfect family. 



25. With fully developed young within. 26. With yellow encysted (resting) spores. 



27. Portion of the outer wall, with zoospores, some dividing. 



28. Ditto, showing the cilia of the zoospores. 



29. Ditto, a fragment after keeping some time in chloride of calcium, the portions 



around each zoospore tumid. 



30. The same seen obliquely, with the cilia. 



31. Spore with the protoplasm dividing. 32. Ditto, more advanced. 



33. An encysted spore with undivided contents. 



34 . An encysted resting-spore, with yellow contents, probably a subsequent stage of 33 . 



35. Ditto, ruptured by pressure. 



36. A similar resting-spore with conical processes on the outer coat (characterizing 



the V. stellatus, Ehr.). 



