1034 REPORT— 1898. 



conjugation iu Closterium, Cosmarium, Spirogyra, in certain Diatoms, and finally in 

 Actinophn/s, he lias arrived at the conclusion ' that a shifting (Verschiebung) of 

 the time of division into four, together with redaction, is possible in the history 

 of development of organisms.' It will doubtless be necessary later to put a precise 

 meauiug upon the word ' Verschiebung,' and to define how far in given cases it is 

 to be understood as an actual shifting of the event within one line of descent, how 

 far it merely expresses an initial difierence maintained, or it may be, extended, 

 in different lines. Meanwhile, those who accept Professor Strasburger's position 

 will see that while in various evolutionary sequences the reduction may take place 

 at different points in tlie cycle, still it may have settled dowm to a fixed and 

 constant position in any one sequence ; that I conceive to have been the case for 

 the Archegoniate series. The validity of this conclusion does not seem to me to 

 be affected by the diverse state of things seen in so far removed a sequence as that 

 of the brown Algae. 



Here a brief reference must be made to the very beautiful results of Wager 

 on the changes in the zygote of Ci/stopiis candidus, which have been verified and 

 extended by Berlese. Wager states that in this fungus the process of fertilisation 

 does not differ in any essential particular from the process as it takes place in 

 Angiosperms. On the division of the fusion-nucleus of the zj'gote the number of 

 the chromosomes present before division appears to be considerably in excess of 

 the number observed in the nuclei of the oogonium. ' By counting as carefully as 

 possible 20 to 24 or even more appear to be present, and the impression is pro- 

 duced that the number is certainly mucli larger than that observed in the 

 oogonium.' Divisions of the nucleus then follow to form 4, 8, 16, and finally 32, 

 in which condition a period of rest ensues ; and, finally, it appears that a division 

 of each into four follows, to form the nuclei of four spores. Wager believes the 

 reduction to take place at this last division, and Berlese has established a strong 

 probability that such a reduction actually does take place. Plainly these obser- 

 vations are not final or conclusive, and, even if they were, the strict homogeny of 

 this fruit-body with a rudimentary sporophyte of a green plant would not be 

 proved. It must, however, rank at least as an important parallel case, illustrating 

 how the reduction may be effected in a distinct line of descent. 



We see, then, that in green Algoe such as (Edogonium, Spharoplea, and 

 Coleoch(vte certain divisions follow fertilisation, but we are not yet in possession 

 of the nuclear details. I prefer, therefore, to suspend judgment as to the nature 

 of those divisions ; but in view of the peculiar behaviour already seen in other 

 zygotes it may be distinctly anticipated that some form of reduction will be 

 demonstrated at that stage. If that be shown then we shall be right iu recognis- 

 ing in these small cell-bodies the rudimentary correlative of a sporophyte — the sort 

 of beginning from vrhich a neutral generation may have sprung in land-living 

 plants. We cannot go farther tlian this as regards the green Algte until we are 

 in possession of the facts. There is no greater desideratum in morphology at 

 the present moment than a detailed knowledge of the germination of zygotes such 

 as that of (Edoyomum. 



Here I may remark that the admirable observations of Professor Klebs, whom 

 the Section will welcome as a distinguished guest, do not appear to me to touch 

 this question. His very varied and convincing experiments show in a number of 

 Algse and Fungi that, as regards the succession of vegetative and sexual modes of 

 propagation, the experimenter has a very complete control. I do not find, how- 

 ever, any observations of his which touch the behaviour of germinating zygotes of 

 green Algae as regards details of segmentation. I do not mention this as in the 

 least impairing the brilliancy of Professor Klebs's work, but because Professor 

 Ward has brought Klebs's results to bear upon the discussion on antithetic alterna- 

 tion in a manner which I do not think that the facts will support. 



II. Brijophijta. 



Turning now to the Bryophytes, these plants stand at the moment in a some- 

 what discredited position. AVe have been warned by Dr. Scott that ' there is no 

 reason to believe that the Bryophyta, as we know them, were the precursors of 



