12 PJBOCEEDINGS OF THE 



The former view, which is often tacitly assumed, meets with 

 difficTilties in the more complex explanation of the transmission 

 of characters which it involves ; in the similar bodies, in spite of 

 the nuclear difference, of the two generations of Dictyota, etc. ; 

 in the diiFerent bodies with no nuclear difference, in certain 

 abnormal ferns. 



The latter view allows of a simpler explanation of the trans- 

 mission of characters ; is consistent with similar bodies being 

 developed from the haploid and diploid germ-cells when exposed 

 to the same conditions, as in Dictyota ; and with the results of 

 their development being profoundly different, as in archegoniate 

 plants. In the latter the zygote, retained within the body of the 

 gametophyte, is removed from all the influences acting on the 

 spore and exposed to a new set of nutritive and correlative influ- 

 ences proceeding from the enclosing body of the sexual individual. 

 These influences last until a condition of formative induction may 

 fairly be supposed to be established. 



The mode of reproduction — sexuality or spore-production — 

 appears to be necessarily associated with the state — haploid or 

 diploid — of the specific cell. In the hght of this ontogenetic view 

 of the origin of the diff'erence between the t\^o generations, 

 examples of the Algae, Hepaticae, Musci, Lycopodiales, Equisetales, 

 and Filicales were considered as well as the facts regarding 

 apogamy and aposporj'. Comparisons were suggested between the 

 two generations in the several groups. 



The bearing of the ontogenetic view on the antithetic and 

 homologous theories as at pi'eseut regarded was then considered. 

 "While the possibility of the different states of the specific cell in 

 the spore and zygote having some causal influence on the difference 

 of the resulting individuals must be borne in mind, it is suggested 

 that this ontogenetic theory of the natui-e of the alternation seen 

 in Bryophyta and Pteridophyta may prove a useful working 

 hypothesis, that it will lead to work on new lines, and that it is 

 to some extent open to experimental test. 



An animated discussion followed, the speakers being Prof. P. 

 O. Bower. Dr. D. H. Scott, P.L.S., Prof. J. Bretland Parmer, 

 Prof. P. W. Ohver, and Mr. A. G. Tansley, Dr. Lang briefly 

 replying. 



March 4th, 1909. 



Dr. D. H. ScoiT, F.E.S., President, in the Chair. 



The Minutes of the G-eneral Meeting of the 18th Pebruary, 1909, 

 were read and confirmed. 



Mr. Henry Caracciolo, P.E.S., C.M.Z.S., Mr. John Beavis 

 Groom, and Dr. Anstruther Abercrombie Lawson, B.Sc, Ph.D., 

 were proposed as Pellows. 



