100 MR. MIERS ON SEVERAL INSTANCES OF ANOMALOUS DEVELOPMENT 
by its pressure a corresponding groove close to the periphery of the albumen: the 
margins of the large cavity in the albumen, in which the much smaller embryo is 
suspended, also correspond with this line of circuit of the raphe, so that the albumen 
along this line is reduced to a very thin substance, and consequently is nearly separated 
into two parallel slabs. In Stemonurus I could not perceive the indication of any 
chalaza at either extremity of the inner integument, and there exists a more intimate 
union of this integument with the testa, which are both of delicate texture. In Pennantia, 
on the contrary, a distinct chalaza is visible at the cotyledonary extremity of the inner 
integument at the vanishing point of the dorsal raphe: the same exists in Mappia, and 
probably in all other genera of the Icacinacee. Mr. Bennett (Plant. Jav. rar. 131) 
quotes the observations of Mr. Brown and of M. Brongniart to show that the eversion of 
the raphe upon the dorsal face of the seed is of frequent occurrence in Celastraceæ, 
Rhamnacee, Aquifoliaceæ, and Caprifoliaceæ, and is fully confirmed by his own experience 
in the seeds of Euonymus and Rhamnus, where it is frequently everted, though often only 
laterally displaced ; and he entirely adopts the opinion of Mr. Brown, that this eversion of - 
the raphe in no way militates against the universal law of anatropal development ; for on 
examining these occurrences at an early stage of their growth, he invariably found the 
ovule with its raphe on the ventral side, or that next the placenta, and he observed that 
its subsequent appearance on the opposite or dorsal face, is due to an evident torsion of 
the upper extremity of the raphe, or short funiculus, during the increment of the seed, 
and not to any original development. The eversion of the raphe in the Jcacinacee, 
together with a Similarity in other essential points of structure, strongly prove the close 
affinity of this order to the Celastraceæ, Aquifoliacee, and other families which I proposed 
to img : buen s deron un (the Dryales), nearly allied to the Rhamnacee. 
pe : oned structure in Stemonurus, a curious deviation from the usual 
evelopmen of anatropous seeds occurs. In the organization of most of its parts there 
exists, as before mentioned, a perfect analogy with that found in Pennantia : the seed is 
albuminous, and the radicle of the embryo is superior and pointed to the hilum ; but while 
in Pennantia we trace the raphe in a straight line to the opposite or cotyledonary extremity, 
R^ red anatropous seeds, we find in Stemonurus, owing to the singular retroversion 
er > AS m Wee. beyond the point where it ought to have 
rn q escent. 9 the summit—to the point of its disappearance 
— de that this unusual eircumstance is not attended by a corresponding 
ag e es eer rine mr 
inversion of the embryo and its amet eum i Aper s ER 
We not see, from the course of the rod ih esee ius, imm d ee Eu 
er Saeed 9, an indication that a complete 
ae n op action of one or both of the integuments has occurred, while 
SE es . Ri ~ deg effected only a half-gyration, or simple anatropal move- 
E eura therwise account for the peculiar form of the raphe in this case? 
s: again to this point when I come to speak of other developments which appear 
ofer much analogy with this phænomenon. å : 
In ord: des ` 
er to prepare the way for this investigation, it is of some interest to determine 
