48 BOTANICAL GAZETTE [yuLy 
Fic. 22.—Archegonium initial. 205. 
Fic. 23.—Part of a longitudinal section of a mature prothallus, showing the 
pollen tube, the basal group of archegonia, and three accessory archegonia; the 
nuclei of all the basal archegonia are dividing. X 120. 
Fic. 23a.—The body cell of fig. 23. 825. 
Fic. 24.—Part of one of the archegonia of fig. 23, showing the spindle con- 
cerned in cutting off the ventral canal nucleus. X825. 
Fic. 25.—The neck of an archegonium in transverse section. 205. 
Fics. 26, 27.—Dividing nuclei in the prothallus cells. % 1500. 
Fic, 28.—Mature archegonium; the position of the pollen tube is indicated — 
above the neck. X 360. q 
Fic. 29.— Young pollen tube; only a single nucleus is present. * 480. 
Fic. 30 —Tip of young pollen tube showing three nuclei. 825. 
Fic. 31.—Part of nucellus, showing position of the tube of fig. 30. X50. 
Fig. 32.—Young pollen tube with body cell and two sterile nuclei; the posi- 
tion of this tube is shown in fig. 17. 825. 
PLATE III 
Fic. 33.—Tip of pollen tube just entering the prothallus. 205. 
Fic. 34.—Tip of pollen tube after growth of the tube has ceased; the sterile 
nuclei with their surrounding cytoplasm form a distinct cell; a small fragment — 
of the body cell nucleus has separated off. 205 
Fic. 35.—The body cell nucleus of fig. 34. oe 25. | 
Fic. 36.—Tip of mature pollen tube, ribs position of male cells and the 
relation of archegonia to the pollen tube. X 205. % 
FIG. 37.—Male cells of fig. 36. 480 
Fic. 38 —Part of a transverse section of a prothallus, showing an archegonium 
containing two free nuclei, the daughter nuclei of the oospore. X 3 
1G. 39.—Diagrammatic longitudinal section of promsbiesa with five nuclei; 
reconstructed from serial sections. 170. 
Fic. 40.—Similar section of proembryo with ten nuclei; reconstructed from 
serial sections. 230. 
1G. 41.—One of the sections from which fig. 39 was constructed, slightly 
oblique: rabies the upper four nuclei and the cleavage planes (?) between 
them Co : 
Fic. Woting seedling. Xr. : 
Fic. . PSO: of same. X3.7. 
1G. 44.—Abnormal pollen tube “ee text). X50. 
Fics. 44a, b.—Nuclei of fig. 44. 
Fic. 45.—Abnormal De A sae 
Fic. 45a.—Part of fig. 45 (see text). 825. : 
Fics. 46a, b.—Two adjacent sections of the nucleus of an abnormal arche- 
gonium. 825. 
