182 The Meeting of the British Association at York. 
by most cytologists—that the nucleus rather than the cytoplasm is 
the carrier of the hereditary properties. He referred to the fact 
that the work of Boveri on the fertilization of enucleate fragments 
of Echinoderm eggs had been contradicted by later workers, who 
had found that the larval stages resulting from such fertilizations 
might exhibit maternal characters. 
Mr. Wager suggested that the sexual unions which are absent 
in such forms as the Cyanophyceae might he replaced physiologically 
by the temporary saprophytic mode of life which is exhibited by 
some of these organisms. 
Mr. Blackman, owing to the lateness of the hour, replied very 
shortly. He pointed out that it was perfectly clear that many 
organisms exhibited no syngamic process in their life-history, so 
that very direct evidence was required to prove that it was necessary 
to other organisms or that it had to be physiologically replaced by 
some other process. As to the evidence that the nucleus was the 
carrier of the hereditary properties he admitted that it was very 
largely indirect, hut nevertheless it appeared overwhelming ; for 
additional evidence obtained in recent times he would refer Professor 
Hickson particularly to the work of Boveri on doubly-fertilized 
eggs which he had described in his opening paper. He referred 
Professor Johannsen to the recent well authenticated evidence for 
the existence of a graft-hybrid between Mespilus and Cnitcrgus. 
Discussion on the Vascular Structure of Seedlings. 
The third discussion took place on Tuesday morning and was 
on the phylogenetic value of the vascular structure of seedlings. 
Mr. T. G. Hill read a paper, by himself and Miss de Fraine, 
“ On the Seedling Structure of Gymnosperms.” The observations 
of the authors’ were confined to the Conifers. The details of the 
behaviour of the cotyledon-traces in their passage to the vascular 
cylinder of the primary root cannot be made clear in an account 
like the present, but it may be stated that the plan of structure 
revealed shews certain common features, and that the anatomical 
evidence leads to the conclusion that the cotyledons of the “poly- 
cotyledonous” conifers are, in some cases at least, derived by splitting 
from a primitive “dicotyledonous” type. In another paper “On 
the Seedling Structure of certain Centrospermre ” of whose con¬ 
tents, owing to lack of time, only the briefest indication was given, 
