202 Rhodora [Jury 
NOTES ON THE EMBRYOLOGY OF SOME NEW ENG- 
LAND ORCHIDS.' 
R. G. LEAVITT. 
(Plate 33.) 
Ow1nc to the fact that work on the native orchids was planned 
late last season, the material at present in hand represents only 
advanced stages in the development of the embryo in most cases. 
Yet even this has shown some things that are of considerable inter- 
est. The remarkable diversity which prevails in orchids with 
respect to the suspensor is well illustrated; and the ripened seeds 
have shown so many instances of polyembryony of a particular type 
that one might suspect such polyembryony of being a family charac- 
teristic. 
GOODYERA TESSELATA and PUBESCENS. The embryos of both 
these species (Figs. 1, 3, 4) seem to lack the suspensor. That 
such is the case with G. pubescens is clearly indicated by the few- 
celled stage represented in Fig. 3. The hemispherical terminal cell 
(c) doubtless represents the suspensor: but it goes to form a 
permanent part of the embryo proper. In G. discolor, according to 
Treub,” this cell pushes out of the embryo-sac, elongates to thrice 
the length of the mature embryo, and serves to bring food-matters 
from the basal region of the developing seed, to the coat of which 
it is closely applied, though it does not reach the ovary wall itself, 
the source of supplies. 
Listera ovata and Epipactis palustris are figured by Treub3 and are 
shown to develop no suspensor. So that we have with Sfzranthes 
cernua and the (probable) case of Goodyera pubescens representatives 
of four nearly related genera in which all cells derived from the 
fertilized egg are included within the germ itself. Usually in 
angiosperms the egg-cell after fertilization divides transversely into 
two cells. The one toward the centre of the sac (“embryo-cell”) 
ultimately gives rise to a large part, and sometimes to the whole, of 
the embryo proper. The other produces the suspensor, generally a 
row of cells attached by the end to the wall of the sac, and acting to 
! Continued from p. 63. 
? Notes sur l'embryogenie de quelques Orchidées, pl. IV. 
? Op. cit., pl. IT., III. 
