﻿i 9 i6] CHAMBERLAIN— STANGERIA PARADOXA 371 



7. Matte, H., Recherches sur l'appareil libero-ligneux des Cycadees. pp. 

 233. ph. 16. figs. 264. 1904. 



8. Miyake, K., Uber die Spermatozoiden von Cycas revolula. Beri Deutsch. 

 Bot. Gesells. 24:74-83. pi. 6. 1906. 



9. Pearson, H. H. W., Notes on South African cycads. I. Trans. South 

 African Phil. Soc. 16:341-354. pis. 6-8. 1906. 



10. Nash, G. V., A rare cycad. Jour. N.Y. Bot. Card. 10:163, 164. 1909. 



11. Chamberlain, C. J., Spermatogenesis in Dioon edule. Bot. Gaz. 47: 215- 

 236. pis. 15-18. 1909. 



12. , Fertilization and embryogeny in Dioon edule. Bot. Gaz. 50: 



415-429- pis. 14-17- 1910. 



13- , The adult cycad trunk. Bot. Gaz. 52:81-104. 191 1. 



14. Hutchinson, A. H., Fertilization in Abies balsamea. Bot. Gaz. 60:457- 

 472- Ph. 16-20. i 9 i S . 



EXPLANATION OF PLATES XXIV-XXVI 

 Most of the sections were cut at 5 fx; none was thicker than 10 ft. With 

 the exception of figs. 4-8, the drawings were reconstructed from two or more 



proembryos. 



Fig. i.— Text cut, showing Stangeria in the field. 



Fig. 2.— Nucellus with pollen tubes showing prothallial cell, stalk cell, 

 body cell with blepharoplasts, and tube nucleus; in one tube (at the right) 

 the body cell has divided; X 50. 



Fig. 3.— Later stage: mature sperms are about to be shed; X50. 



Fig. 4— Blepharoplast, much vacuolated, shortly before breaking up 

 into granules; the body cell has not yet divided; X365- 



Fig. 5— The blepharoplast has broken up into an immense number of 



plast of the preceding figure; the median portion of the spindle can still be 

 seen; X365. 



Fig. 6.— The granules have increased in size and number and are becoming 



X365. t0 a n0tC 1 g 



Fig. 7.— Transverse section of a band at.the stage shown in fig. 6; X365. 



Fig. 8.— The bristle-like cilia beginning to develop from the band; some 

 are directed toward the nucleus; X365. 



Fig. 9 — Fertilization: the sperm nucleus entering the egg nucleus; the 

 ciliated band remains at the top of the egg; X42. 



Fig. 10.— First mitosis in the fertilized egg: at the top, 3 sperms which 

 have passed through the neck, but have not entered the egg; the ciliated band 



