Mr. H. J. Carter on Fecundation in Volvox. 19 



shows also the starch-cells, vibrating brownish granules in the 

 reticular cavities, anil marbled appearance of the chlorophyll and 

 protoplasm. To contrast with fig. 6 c, of the same size. 



Fig. 5. Volvox stellatus, daughter of, some little time after expulsion, and 

 before the great-grand-daughters or fourth family have appeared. 

 To contrast with tig, 3. 



Fig. C. Ditto, daughter of; more magnified view of the grand-daughter of 

 fig. 2, 2-5400ths of an inch in diameter, to show that the gonimic 

 contents already present the first line of segmentation, while 

 those of the grand-daughter of V. globator (fig. 4) have reached 

 18-5400ths of an inch before transformation into distinct cells : 

 a & 6, magnified view of the grand-daughter on the same scale — 

 thus showing the relative sizes of the three first stages of dupli- 

 cative subdivision ; c, last stage of duplicative subdivision, nearly, 

 before the fourth family appears, 18-5400ths of an inch in dia- 

 meter. To contrast with fig. 4. 



Fig. 7. Volvox globator, spore-bearing daughter of, some time after expul- 

 sion ; largest size seen 45-1880ths of an inch in diameter ; spores 

 3-1880ths of an inch in diameter (the whole number of sjjores 

 are not inserted here) : a, more magnified view of spore after 

 impregnation, showing the irregular form of the capsule. 



Fig. 8. Ditto, spermatic-cell-bearing daughter of {Sphccrosira Volvox, 

 Ehr.); largest size seen, 20-1880ths of an inch in diameter: 

 a, spermatic cells, 3-1880ths of an inch in diameter : the whole 

 are not inserted here. Besides the spermatic and peripheral 

 cells, there are always several others of intermediate size, b, form 

 of spermatozoid, 2 to 2'5-5400ths of an inch long. 



Fig. 9. Volvox stellatus, daughter of, bearing spores and spermatic cells 

 together ; largest size 50-1880ths of an inch long, and 44-1880ths 

 broad ; spores 2 to 2"5-18S0ths of an inch in diameter : b, b, b, b, 

 spermatic cells, each 3-1880ths of an inch in diameter (neither 

 all the spores nor all the spermatic cells are inserted) ; c, more 

 magnified view of spore, after impregnation, showing the stellose 

 capsule, — thus still pointing out the tendency to the conical or 

 elongated form which exists in this species, in contradistinction 

 to that of the other, which is globular or spherical; d, form of 

 spermatozoid, 2'3-5400ths of an inch long. 



Fig. 10. Spermatic cell after the development of the spermatozoids, but 

 before their separation, 3-1880ths of an inch in diameter; this 

 is the same in both species : a shows a lateral view of the group, 

 with the dark point representing the remains of the eye-spot of 

 the parent ; b, vertical view of same. 



Fig. 11. Portion of peripheral cells from V. stellatus, showing that the 

 daughter-cell, a, is an enlargement of one of them. 



Fig. 12. Spongilla plumosa, monociliated spiniferous cell of, bearing por- 

 tions of indigo ; 1 -6750th of an inch in diameter. 



Fig. 13. S. alba, "spherical sac" of; l-385th of an inch in diameter: 



a, presenting a cortical portion of monociliated, spiniferous, and 



b, unciliated sponge-cells and granules. 



Fig. 14. Ditto, cortical portion of, consisting of four monociliated spini- 

 ferous cells. 



Fig. 15. Euglena fusiformis, n. sp. ; 8-5400ths long, 5-5400ths of an inch 

 broad: a, a, "glair-cells;" b, contractile vesicle and eye-spot. 



Fig. 16. E. zonalis, n. sp. ; 6-5400ths long, including tail: a, a, glair- 

 cells ; b, contractile vesicle and eye-spot. 



Fig. 17. E. fusiformis, transverse section of, to show the zonular position 



2* 



