Marcu 4, 1897 | 
‘The Begonias are, as is well known, propagated from leaves to 
a large extent in our greenhouses; the Hoya carnosa and the 
Acuba japonica exhibit the same phenomenon. 
Buds are formed on the roots of trees, shrubs, and herbaceous 
plants, which are capable of the direct production of young plants 
of the same kind as the parent. Every one knows that the 
gardener avails himself of this familiar fact for the purpose of 
increasing his stock in a very large number of plants. One 
point only requires further mention, viz. that the tendency to 
produce young plants from roots is in some cases produced, and 
in others is greatly increased by the destruction of the parent 
plant. This seems to show that the same cells or parts of the 
plant which, during the continued life of the parent, assisted in 
its vital functions, have, by reason of its destruction or death, 
been diverted to new duties. The same part, therefore, is alike 
adapted to, or at least capable of, nutrition and reproduction. 
Buds are formed on and around the underground bulbs of 
a large number of plants; no mode of reproduction is more 
familiar to our gardeners. 
Buds, again, are produced in some cases on the subterranean 
stems, as in Ste//arza bulbosa. 
In many cases flowers are replaced by bulbils : Polygonwze 
viveparum and bulbiforum, Saxifraga cernua, nivalés and 
stellaris, Juncus alpinus and supinus, Aira alpina, Festuca 
alpina and rupicaprina, Poa alpina and conzsta are cases in 
which perfectly formed flowers are often produced, but in which 
small bulbils frequently, and especially in alpine or arctic 
regions, take the place of the flowers. (2 Kerner by Oliver, 
454.) These bulbils are detached from the parent plant, and 
throw roots downwards and stems and foliage upwards. A 
somewhat analogous growth kas been found in the Vymphea 
Zotus var. monstrosa (Barber, ‘‘On a Change of Flowers to 
Tubers in Vymphea lotus var. monstrosa,” Ann. Bot. iv. 105). 
After the development of the sepals, instead of the production of 
petals and stamens there was formed a bud of green leaves, 
which developed into a tuber from which a young plant arose. 
In the persistence of the flower’s stalk and sepals, this case 
differs from that presented by such plants as the Polygonum 
wiviparum. 
Lastly, one of the most interesting cases of vegetative repro- 
duction is that of parthenogenesis, or the production of seeds by 
the female plant without the co-operation of pollen. This 
appears to be established beyond doubt in the case of the 
Celebogyne zlécéfolia, and probably in the cases of the hemp 
the Mercurialis annua and Graphalium alpinum. This mode 
of reproduction strikes the mind as very remarkable, because it 
shows that even in very highly organised plants parts which 
had been specially provided for reproduction under the stimulus 
of the pollen cell, still retain the capacity of reproduction even 
without that stimulus. 
It is obvious from these familiar facts that the capacity of re- 
production is retained by a great part of the organism in many 
plants, and that it is not excluded by the fact that the part in 
question may be highly and definitely organised for some other 
purpose than reproduction, or that it may be intended, according 
to the analogy and the common course of nature, for reproduction 
only after the stimulus of fertilisation. 
CONCLUSIONS. 
The doctrine (to use an ambiguous word) of the alternation of 
generations may be regarded in several lights : as a compendious 
statement of facts ; as an analogy ; as something to be inferred in | 
ancestral forms from existing ones. 
If we mean by a generation the life of an independent organ- 
ism from the time when its whole future was gathered up in one 
cell, it seems never to represent the facts of vegetable growth ; 
if by it we mean the dependent life of part of an organism from 
a single cell, it appears to summarise the facts of the full life- 
history of ferns and mosses, but not of the Rhizocarps or of 
Phanerogams. 
If we regard the doctrine as an analogy, the points in which 
the analogy breaks down, and the continued recurrence to excep- 
tions to make it agree with the various facts, seem to rob it of 
much value. 
If the alternation of generations be put before us as a fact 
which the phenomena of existing vegetable life require us to 
assume in the past, it seems at least doubtful whether more can 
be justly said than that amongst many modes of reproduction 
and many schemes of life-history, an alternation of generations 
an the sense in which it exists in the mosses and ferns may 
NO. 1427, VOL. 55 
NATURE ae 
probably be considered as one; but there seems to be nothing 
to show that it was ever a dominant scheme of life. 
The brief review of familiar facts above given seems to tend 
towards the following conclusions, which I submit with all 
deference to those better capable of appreciating the question 
than I am. 
_ (1) That in the language of Prof. Bower, ‘‘no fixed and 
impenetrable barrier exists between sporophore and oophore,” 
but that, on the contrary, the one is capable of passing over to 
the other, and that the alternation of generations is not an 
accurate statement of facts or a useful analogy. 
(2) That a truer presentation of the facts is to be found in the 
statement that fertilisation in a plant does not always result in 
the direct production of a fertilised ovum capable of producing 
the cormophyte, as in the Characee and the phanerogams, 
but that it may result in the indirect production of a number 
of fertilised cells, as in the mosses and some fungi, or, as an 
alternative view of the same facts, in the direct production of 
a new part of an existing organism. 
(3) That (to repeat the foregoing statement in another form) 
the different generations in the life-history of any given plant 
are not separate organisms, but different stages or parts of the 
same organism. 
(4) That when the like events can be found in the life- 
history of different plants, the order of the succession of events 
is unstable, and that the first may become last and the last 
first, according as the physiological circumstances of the plant 
give scope for the action of that reproductive capacity with 
which the whole plant seems to be endowed. 
(5) That this instability exists, even in the sexual act, as 
regards its place and time in the order of the succession of 
events. 
(6) That the events which occur in the full life-history of a 
plant admit of short-circuiting or abbreviation, and that in such 
abbreviated life-histories the one thing which nature appears to 
desire to avoid is the sexual act, and that the one thing which 
it appears to desire to preserve is the cormophyte. 
(7) That the passage from.the life-history of the moss to that 
of the fern may be accounted for by a transposition in the order 
of events, and that by such a transposition a moss may be re- 
garded phylogenetically as the direct ancestor of the filmy fern, 
and the indirect ancestor of all the other ferns. 
(8) That, assuming that there is a germ plasm distinct from 
somatic plasm, and that the presence of the former is essential 
for the reproduction of the organism, there is evidence of the 
wide diffusion of the germ plasm, and that no limit to its 
presence has yet been ascertained. 
(9) And lastly, that the reproductive energy operates in plants 
in such a variety of ways, and under such varying circumstances, 
as to make it improbable that the facts of reproduction can, 
with our present knowledge, be reduced to any one scheme, or 
referred to any single archetype. Epw. Fry. 
UNIVERSITY AND EDUCATIONAL 
INTELLIGENCE. 
Oxrorp.—On Tuesday, February 16, Convocation decided 
to confer by decree the dezree of M.A. on Dr. J. S. Haldane, 
Lecturer in Physiology, and on Dr. W. B. Benham, Aldrichian 
Demonstrator in Comparative Anatomy. 
Messrs. W. W. Fisher (C.C.C.), W. Hatchett-Jackson 
(Keble), W. S. Church (Ch. Ch.), W. Collier (Exeter), S. H. 
West (Ch. Ch.), J. E. Marsh (Balliol), and G. W. S. Farmer 
(Balliol) have been elected members of the Board of the Faculty 
of Medicine. 
The following have been elected Members of the Board of 
the Faculty of Natural Science :—Messrs. C. Leudesdor (Fellow 
of Pembroke), D. H. Nagel (Fellow of Trinity), E. H. Hayes 
(Fellow of New Coll.), J. W. Russell (Merton), J. Walker 
(Ch. Ch.), F. J. Jervis Smith (Trinity), A. Thomson (Exeter, 
Professor of Human Anatomy), W. W. Fisher (C.C.C.), and 
V. Il. Veley (University). Fr 
On Monday, March 1, Prof. E. E. Barnard exhibited some 
of his astronomical photographs in the Examination Schools, 
Mr. A. C. Le Rossignol (Exeter Coll.) has been elected to 
an Exhibition in Natural Science at Exeter College on the 
foundation of King Charles I. ; 
Captain W. de W. Abney, C.B., F. R.S., has accepted the in- 
vitation of the Junior Scientific Club to deliver the Robert 
Boyle Lecture for 1897. 
