G. i?. Wieland — Notes on Living Cycads. 337 



plainly belonged showed a strengthening of the vascular 

 bundles next the border in contact with the base of the pinnule. 

 But this part had suffered from wilting, so that I could not get 

 as good evidence of attachment as I could have wished. For 

 the sake of exactness I must explain therefore, that while my 

 figure 5 without doubt represents faithfully the condition 

 of several weeks earlier, 

 it is not the condition 

 found when the cone was 

 examined. 



This pinnule did not 

 therefore grow in the ex- 

 act position of the ovule 

 in a normal and fertile _ 



i ii -i , • Figure 5. — Zamia floridana DC. x ^. 



sporopnyil DUt proxi- S porophyll (a) and pinnule shown in figure 4. 



mally on the same bor- 

 der. The two outer angles of the sporophyllar rachis may 

 then be considered as being at once spore- or pinnule-bearing. 

 The evidence that the entire structure is a modified pinnate 

 leaf, just as in the case of the carpophylls of Cycas, is over- 

 whelming. 



The first example of such monstrous cycad cones recorded, 

 so far as I am aware, is that of an Encephalartos villosus Lem. 

 described and figured by Sir W. T. Thiselton-Dyer in the 

 Annals of Botany (vol. xv, JSTo. lix, Sept., 1901, p. 549). In 

 this case there is a very extended reversion. The barren sporo- 

 phylls of the summit of the cone become more and more 

 frond-like, until one of them rises as a distinct once pinnate 

 frond. Although truncated, and reduced in size, this frond 

 presents all the essential characters seen in the frond of E. 

 villosus. The twelve pinnules it bears are expanded and notched 

 in a normal manner. "The other modified carpels present," 

 says Thiselton-Dyer, "are however so generalized that without 

 the help of the more fully developed leaf their equivalence 

 would be scarcely intelligible. This much is clear: the solid 

 expanded peltate carpophyll is nothing more than a trans- 

 formed foliage leaf and capable of being replaced by UP The 

 italics are mine. 



The significance of such structures is unmistakable. To 

 speak of these growths as u monstrous cones " is almost mis-, 

 leading. They are simply reversions exhibiting evolutionary 

 stages which may at any time be found in fossilized forms of 

 the ancestral line. When an Encephalartos reverts we find 

 the growth preserving unmistakable characters of its genus and 

 species; and likewise in the quite different form of reversion 

 just described in Zamia the phenomenon falls within the same 

 category. The main specific characters are preserved. 



