1908] KILDAHL—PHYLLOCLADUS ALPINUS 347: 
19. ———, Studies in the morphology of Torreya californica. II. The sexual 
organs and fertilization. New Phytol. 3: 205-216. pls. 7-9. 1904 
20. Younc, Mary S., The male gametophyte of Dacrydium. Bor. GAzETTE 
44:189-196. pl. 19. 1907. 
EXPLANATION OF PLATES XX-XXII 
With the exception of figs. 1 and 2 all the figures were drawn with the aid 
of a camera lucida and reduced one-half. Index letters are as follows: e, endo- 
perm; ~, perisperm; #, nucellus; e inner fleshy layer; s, stony layer; of, 
outer fleshy layer; a, arillus; fs, -— cale 
TE XX 
Fic. 1.—Abaxial view of oe showing the empty sporangia. 
Fic. 2.—Side view of microsporophyll. 
Fic. 3.—Microspore. 1850. 
Fic. 4.—First division of microspore. X1850. 
Fic. 5.—Two-nucleate stage. 1850. 
Fic. 6.—Second division; first prothallial cell against upper wall. 1850. 
Fic. 7.—Three-nucleate stage, showing form of wings. X 3000. 
Fic. 8.—Evanescent walls of the two prothallial cells. 3000 
Fic. 9.—First evanescent prothallial cell lying outside of the cytoplasm of 
the spore. X18s0. 
Fic. 10.—Mature microspore. 1850. 
Fic. 11.—Microspore with both prothallial cells retained. 3000. 
Fic. 12. —Phylloclad with ovulate strobilus. 
Fic. 13.—Outer view of fleshy scale with ovule. 
Fic. 14.—Inner view of fleshy scale with ovule, showing arillus 
Fic. 15, —Longitudinal section of ovulate strobilus, dione ovules with 
integuments, fleshy scales, and position of vascular system, November 1. X40. 
Fic. 16. poms geckos of ovule; archegonia in the center of the endosperm; 
November Tae. 
Fic. 17 .—Longitudinal section of the ovule with fleshy scales; micropyle not 
yet formed; arillus covering the ovule; November 1. X40. 
PLATE XXI 
Fic. 18.—Part of nucellus on November 1, showing pollen tubes and part of 
the female gametophyte in the free nuclear stage; archegonia not yet formed; 
body cell not yet divided. X850. 
Fic. 19.—Nucellus showing numerous: pollen tubes and open archegonia; 
nearly all the body cells have divided; December 11. X1 
Fic. 20.—Pollen tube, containing two male nuclei, the stalk and tube nuclei, 
and one prothallial nucleus, entering the archegonium. Sees 
Fic. 21 -—Archegonial jacket cells. 3000; fig. 214, 
Fic. 22. Fertilization: the fusing nuclei are saitatly ‘eanmies by the 
Cytoplasmic sheath; the second male nucleus lies above the fusing nuclei and has 
n to depenerate. X 3000. 
