62 SIR J. LUBBOCK —PHYTOBIOLOGICAL OBSERVATIONS. 
Phytobiologigal Observations; On the Forms of Seedlings and 
the Causes to which they are due.—Part II. By Sir Joun 
Lussdék, Bart., V.P.L.S., F.R.S., M.P., D.C.L., LL.D. 
[Read 17th February, 1887.] 
INFLUENCE OF THE LEAF ON THE COTYLEDON. 
Seedlings of Onagrariec. 
Some of the Onagrariee have seedlings with very curious coty- 
ledons. For instance, I was greatly puzzled by the seedling of 
Gnothera bistorta, in which (fig. 135) the cotyledons were long 
Fig. 135. 
Seedling of (Enothera bistorta. x3. 
and linear, suddenly widening at the end into a large orbicular 
expansion, which gives them a very peculiar appearance. 
In Eucharidium grandiflorum (fig. 138) or Clarkia rhomboidea 
(fig. 143) the form of the cotyledon might not unnaturally be sup- 
posed to be a case similar to that of Malva. In reality, however, 
the explanation is very different. In Eucharidium the lobes have 
nothing to do with the arrangement of the embryo in the seed. 
The young plant, indeed, immediately after germination, presents 
no trace of them. The cotyledons, when they first emerge from 
the seed (fig. 136), are oblong-orbicular, sessile, cordate or auricled 
at the base, and emarginate at the apex, with a small purple tooth 
in the notch ; they grow rather rapidly, become shortly petioled, 
and develop one or two lateral, incurved nerves on each side of 
the midrib. 
In the next stage, about eight days after germination, they 
exhibit a very slight constriction near the base of the cotyledons, 
with a small obtuse tooth. This basal portion increases much more 
rapidly, while the growth of the terminal portion (which is, in fact, 
the original cotyledon) becomes gradually arrested. The tooth 
