1. The Microgametophyte of the Podocarpineæ,
The species dealt with were Podocarpus polystachya (material from Java), P. ferrugineus, P. dacrydioides, Dacrydium Bidwilln, and, for comparative purposes, Agathis australis (material from New Zealand).
The conclusions reached by the authors are:—
The Podocarpineœ, as represented by Podocarpus and Dacrydium, are characterized by a proliferation of the two original prothallial cells through more or less numerous anticlinal divisions.
The anticlinal proliferation of the prothallial cells is accompanied by a similar proliferation of the generative cell, an abnormality which appears to have been described in no other Gymnosperms.
Similar proliferation of the two original prothallial cells has been observed in the araucarian genus Agathis.
The proliferation of the two prothallial cells in the Podocarpineœ and the Araucarineœ, and the proliferation of the generative cell in certain species of Podocarpus, cannot be regarded as a primitive feature.
The ground-plan of microgametophytic development found in the Podocarpineœ and Araucarineœ points to their derivation from an ancestral stock allied to the Abietineœ.
Since the Podocarpineœ and Araucarineœ present many features of similarity in general habit, in geographical distribution, in the organization of their megasporophylls, and the development of their microgametophytes, it seems not improbable that they are somewhat more nearly allied than has been supposed.