﻿1903] EM BR 



193 



embryog-eny of Ginkgo is the most primitive one among gymno- 

 sperms ; that the embryogeny of Cycas is more primitive than 

 thatofZamia; that in its embryogeny Zamia approaches more 

 nearly the Coniferales than does Cycas; that such forms as 

 Taxus, Cephalotaxus, Pqdocarpus, Taxodium, and Thuja show 

 progressive stages of embryogeny from that of Zamia toward 

 that of Pinus ; that Ephedra has the most primitive embryogcn}' 

 among the Gnetales; and that Gnetum and Tumboa resemble 

 the angiosperms in the elimination of free nuclear division from 

 their embryogeny. 



University of Chicago. 



^ LITERATURE CITED. 



1. Strasburger, E., Die Coniferen und die Gnetaceen. 1872. 



^- -, Ueber Zellbildung und Zelltheilung. 1876. 



3. Warming, E., Recherches et remarques sur les Cycadees. Oversigter 



over d. K. D. Vidensk. Selsk. Forh. 1877. 

 4- , Ein Paar nachtragliche Notizen uber die Entwickelung den Cyca- 



deen. Bot. Zeit. 36: 737-739. 1878. 



5. Tkeub, M,, Recherches sur les Cycadees. 3. EmbryogSnie du Cycas circi- 



nalis. Ann. Jard, Bot. Buitenzorg 4 : i-w, pis, i-j. 1884. 



6. Ikeno. S., Vorlaufige Mittheilung uber die Canalzellbildung bei Cycas 



revoluta. Bot. Centralbl. 67: 193-194. 1896. 



7. Webber, H. J„ Notes on the fecundation of Zamia and the pollen tube 



apparatus of Ginkgo. Bot. Gaz. 24:225-235.//. 20. 1897. 

 S. Ikeno, S., Untersuchungen liber die Entwickelung der Geschlechtsorgane 



und der Vorgang der Befruchtung bei Cycas revoluta. Jahrb. Wiss. 



Bot. 32:557-602.^/5. 5-70. 1898. 

 9. Armoldi, W., Beitrage zur Morphologic der Gymnospermen. III. Em- 



bryogenie von Cephalotaxus Fortiinei. Flora 87: 46-63. pis. 1-3^ 

 1 900. 

 10. Ikeno, S., Contribution a Tetude de la f^condation chez le Ginkgo biloba. 



Ann. Sci. Nat. Bot. VIII. 23:305-318.//?. 2-3, iqoi 



II. Web 



U. S. Dept. 



Agric, Bureau Plant Industry Bull. 2. pp. 100.//. 7- IQO^- 



W 



Bot. Gaz. 33 : 89-107. pis. j-7. 1902. 

 13. Land, W. J. G., A morphological study of Thuja. Box. Gaz. 34 : 249^-59 



pis, 6-8. 1902. 



