APPLICABLE WITHIN LIMITS 185 
cotyledons or protophylls raise any insuperable obstacle in the way of a 
theory of the strobilus as stated in a previous chapter, so long as they 
are held to be anticipatory growths in the sense above explained. 
From the above pages it will be seen that the foundations of recent or 
current embryology of the sporophyte are open to criticism. The analogies 
with animal embryology are misleading: strict recapitulation is not to be 
assumed where, as in plants, continued embryology holds sway: segmenta- 
tion appears to be a phenomenon connected in no obligatory sense with the 
origin of organs: the relative position of the parts of the embryo, though 
it may be fairly uniform in circles of near affinity, is variable according 
to biological requirements which are readily intelligible in the establish- 
ment of the germ: the relative time of origin of the parts may also be 
variable, even within circles of near affinity. The question will therefore 
be what weight in our comparisons is to be accorded to these somewhat 
fluctuating facts of the primary embryogeny of the sporophyte? They 
have been very highly estimated in the past: while not denying their 
value, I think that they have been given altogether undue precedence over 
the characters of the sporophyte which appear later, and this opinion is 
based both on general considerations and on detailed comparison. Accord- 
- ing to the view of alternation advanced above, there does not appear to 
be any sufficient reason for attaching special comparative importance to 
the initial steps of the primary embryology. If it had not been for the 
recapitulation theory of the zoologists, it is improbable that this position 
would ever have been adopted in the case of plants. The more natural 
inference from the facts would probably have been the converse, that is, to 
attach greater weight to the characters of the mature shoot: in fact, the 
position now is that the embryogeny must be interpreted in terms of the 
mature plant rather than the converse which a recapitulation theory would 
demand. For the reasons thus stated the initial embryogeny of the sporo- 
phyte will be accorded only a minor place in our comparisons: when 
once the earlier, and in considerable degree adaptive embryonic phase 
is past, and the form characteristic of the mature plant is by way of 
being established, this would seem to be a more reliable basis for com- 
parison than any minute details of the initial embryogeny.' Probably the 
strobilus itself will give the most trustworthy basis of all. 
But it is not to be concluded that recapitulation plays no part whatever 
in the development of the sporophyte. Seedlings of many plants with 
highly specialised shoots, such as the phyllodineous Acacias, and spinous 
plants such as Cex, start with a postcotyledonary shoot of simple and 
not specialised form, characteristic of the group to which they belong: 
they only assume their peculiarly adaptive character later. They thus 
reflect in some degree in their ontogeny the history of their specialisation. 
Such facts are familiar, and the interpretation generally accepted. But 
1Miss Thomas (ew Phytologist, 1907, p. 77, etc.) has expressed a similar view as 
applied to the embryogeny of Angiosperms. 
