332 G. R. Wieland — Notes on Living Cycads. 



the formation of the motile antherozoids, may be studied for 

 several days after the cones are cut from the parent plant, thus 

 making it possible to study all the phenomena of fructification 

 from cones sent north from Florida, and perhaps even from the 

 more accessible of the West Indies. The crucial dates for Z. 

 floridana, as determined by Webber (loc. cit.), are as follows : 



(1) Pollination takes place the last of December and first of 

 January. 



(2) Germination of pollen and growth of prothallial apparatus 

 from January 1 to June 1. 



(3) Division of second prothallial cell, giving rise to the stalk 

 cell and central cell, February 15 to March 10. 



(4) The blepharoplasts first appear about March 1 to 20. 



(5) The gradual development of the central cell blepharoplasts 

 and prothallial apparatus continues from March 1 to May 30. 



(6) The prophase of division of the central cell appears about 

 May 20 to 25. 



(1) Spermatozoids mature mainly between June 1 and 15. 

 (8) Fecundation takes place mainly between June 1 and 15. 



In the case of Zamia pumila, Webber (loc. cit.) found that 

 in 1897 maturation of the spermatozoids and fecundation took 

 place fully three weeks later than the dates above given, 

 although pollination and the first appearance of the blepharo- 

 plasts occurred at about the same time as in Zamia floridana. 

 The latter is however much more uniformly fertilized. 



The present notes are mainly based on some fifty specimens 

 from the Miami region, obtained for me by Mr. W. S. Dickin- 

 son of Miami, Florida. These arrived in the latter part of 

 November last in good condition for planting. The various 

 plants taken together showed well what an exceedingly inter- 

 esting plant Zamia floridana is in every way. All the trunks 

 were in full and still green foliage, and many bore the already 

 large and fine cones such as are shown in the accompanying 

 illustrations. 



As is well known, among the living cycads we find the 

 largest ovules seen in the vegetable kingdom, although it is 

 wholly significant that these structures are comparatively small 

 in the Bennettitese. In figure 1 the curious fact is well shown 

 that ovulate cones, even many months before the gametophytes 

 are fairly mature, are often distinctly larger than the under- 

 ground trunks which bear them. As a trunk may bear several 

 ovulate cones, this contrast in size may become even greater. 

 Large mature cones are several inches longer than the young 

 unfertilized cones here figured. As in all cases, however, 

 where the sporophylls are closely organized into typical cones, 

 appression faces form, and to a large degree remodel and thus 

 partially conceal the original characters of the component parts, 



