Mr. J. Morris on recent and fossil Cycadecs. Ill 



The family is dioecious. The inflorescence consists of a stro- 

 biliform spike, from the under surface of the scales of which 

 the polleniferous thecoe proceed ; in Zamia these thecae are 

 separated into two distinct masses, -while in Encephalartos 

 and Cycas they form a confluent mass. 



The female inflorescence of Zamia and Encephalartos is 

 similar to the male cones in form, having thick scales, each 

 bearing on the superior surface two naked ovula ; while in 

 Cycas the naked ovula are seated in depressions on the edges 

 of a frond but little altered from the ordinary structure. 



The foliation of this family consists of pinnate fronds, the 

 circinnate vernation of which, in a young state, has generally 

 been considered a character belonging to all the genera ; but 

 a series of observations on the development of the frond which 

 I have had an opportunity of making in several species of the 

 three existing genera, have led me to an opposite conclusion, 

 from which it is evident that even in Cycas itself the rachis is 

 constantly straight in the early state 5 when however tw^elve 

 or more fronds rise together, the outer ones become incurved 

 at their extremities, apparently for the purpose of affording 

 some protection to the more delicate fronds within, w^hich re- 

 main perfectly straight : the only parts to which the term cir- 

 cinnate can be strictly applied, are the young segments or 

 pinnae. In the evolution of the fronds the development pro- 

 ceeds from the base upwards, each pair of pinnae becoming 

 unrolled as soon as that part of the rachis has attained its full 

 degree of extension and size. 



A correct figure of the young frond of C. circinalis is given 

 in Rheede's ^ Hortus Malabaricus,^ vol. iii. 1. 15. f. 2, 3, 4 ; and 

 one of C revoluta is figured in plate xi. fig. 4, 5, ^ Mag. Nat. 

 Hist.^ 1840, from a specimen obtained from Mr. Anderson, of 

 the Chelsea Botanic Garden. 



The prefoliation of Zamia and Encephalartos presents but 

 little difference from each other ; the young rachis is slightly 

 recurved at the apex, the two series of pinnae being regularly 

 imbricated, and applied to, or in contact with, each other by 



great peculiarity of the Coniferae, and which distinguishes them as well from 

 Cycadese as from every other family^ is the remarkahle uniformity of their 

 woody tissue, which consists of slender tubes, furnished on the sides parallel 

 to the medullary rays with one or more rows of circular or angular dots ; 

 but in Cycadeae no such uniformity is observable, their tissue, as in other 

 phsenogamous plants, consisting of two kinds of vessels, namely, of slender 

 transparent tubes, without dots or markings, and of dotted, reticulated and 

 spiral vessels, which are capable of being unrolled. The former are iden- 

 tical with the fibrous or woody tissue ; whilst the latter, which form a part of 

 each bundle, can only be compared to the strictly vascular tissue of other 

 plants."— (Proc. Linn. Soc. Feb. 4, .1840.) 



