1 96 Far 7 ner ci 7 id Digby. — Studies in Apospory and 
of them. In the spore-mother-cells as they are formed in the ovule or 
macrosporangium, provided that these divide into four cells, as phylo- 
genetically speaking they ought to do, then the meiotic phase coincides 
with this division into four potential macrospores. But if the now useless 
stages are cut out, we find meiosis shifted onwards in the ontogeny until, 
as Liliinn candidum for example, it may even coincide with the first two 
divisions of the germinating macrospore, that is to say, it has been shifted 
on to the developing gametophyte. Inasmuch then as it appears that 
no essential relationship subsists between the onset of meiosis and any 
particular stage in the life-history, the question at issue between the 
respective champions of the antithetic and homologous theories, in so 
far as cytological evidence is concerned, remains very much where it was 
before. But notwithstanding this, it seems to us that the attention which 
has become necessarily concentrated on these questions has indicated wider 
points of view, and at least has served to render the real issues somewhat 
clearer. 
It hardly needs pointing out that the views as to alternation are 
in no way affected by the circumstance that in so many of the higher 
plants we meet with exceptions in which the ordinary course of events is not 
adhered to. Thus cells that should have continued to perpetuate their like 
until the final appearance of asexual 1 reproduction may depart from this 
prescribed course, and so, as it were prematurely, may give rise to the next 
(alternate) generation. Amongst the lowest plants such an instance would 
be afforded by a zygote of Oedogo7iiii7n , which should at once grow out into 
an Oedogonial filament, with the omission to produce the four zoospores. 
This might conceivably represent a primitive case of apospory, but if the 
filament thus arising were to reproduce sexually one might pretty safely 
assume that the meiotic phase had not been suppressed, as in the higher 
plants where sexuality correspondingly fails, but that it probably occurred 
on germination, although unaccompanied by the usual formation of asexual 
zoospores. 
The circumstance should not be lost sight of that we are profoundly 
ignorant of the causes that guide the stages of ontogeny, and it seems now 
certain that any cell the nucleus of which is provided with the requisite 
chromosomes, whether these are in single or duplicate number, is 
at least potentially endowed with the capacity of forming the starting- 
point of the entire life-history, in so far as the grosser morphological 
characters are concerned. Thus tissues with premeiotic nuclei can yet 
become transmuted into the generation normally characterized by post- 
1 We use this word to denote those cells which normally terminate the one and form the 
starting-point for the next (sexual) generation. We prefer, according to older usage, to retain the 
spore as the natural boundary between the two generations rather than to adopt the spore-mother- 
cell as such, according to the view suggested by Strasburger in 1894 and supported by some 
distinguished American botanists. 
