﻿Manchester Memoirs, Vol. xlix. (1905), No. VI. 19 



leaved species of AgatJiis, give us probably the best idea 

 of the aspect of the Cordaiteae, though the comparison is 

 not a very close one. 



The anatomical structure of stem and root has on the 

 whole a Coniferous character, the wood being of the well- 

 known Araucarioxylon type. The pith of the stem, how- 

 ever, was large, as in Cycadaceae. The structure of the 

 leaves resembled that of the leaflets of a Cycad. The 

 male catkins bore, among their bracts, stalked tufts of 

 elongated erect pollen-sacs, which may perhaps be most 

 nearly compared, though very different in appearance, to 

 the stamens of Ginkgo. The ovules were borne in small 

 cones, or lax catkins, and appear to have been produced 

 in the axils of bracts, each ovule perhaps terminating a 

 -short axillary shoot. The structure, both of the ovule and 

 of the ripe seed, has been investigated. Here, as in 

 Lagenostoma and other Pteridospermeae, there is a pollen- 

 chamber, in which the pollen-grains are found. It was in 

 the case of Cordaites that M. Renault first observed 

 the multicellular structure of the pollen-grains, and found 

 reason to believe that their growth was continued after 

 they became enclosed in the pollen-chamber of the ovule. 



It is a fact of great interest that M. Renault in 

 discussing the multicellular pollen-grains of Palaeozoic 

 seed-plants, suggested in 1896, that they might have 

 discharged spermatozoids within the pollen-chamber to 

 effect fertilization — a remarkable anticipation of the 

 discovery of motile spermatozoids in recent Cycads and 

 in Ginkgo, announced by Ikeno and Hirase a few months 

 later. (Renault, '56.) 



The seeds of Cordaiteae are flattened, thus differing 

 from the " radiospermic,'' i.e., rounded or cylindric type, 

 which appears to have characterised the Pteridospermeae, 

 In relation to the different form there is also a different 



