of the Vegetable Ovule. 21 



The mode of origin and the changes that take place in the 

 growth of campylotropal and amphitropal ovules, with some 

 modifications, are quite analogous to all that occur in the ana- 

 tropal ; it is, therefore, unnecessary for our present purpose to 

 speak of them ; but in regard to atropal ovules, it is requisite to 

 say a few words. Here the budding-point is at the very apex, 

 not on one side of the placentary sheath ; the nucleus therefore 

 makes its first appearance in a depression at that point, where 

 also the secundine soon surrounds it, while the extremity of the 

 sheath is extended by degrees to form the primine, — all three 

 growing straightforward in the same centrifugal direction ; the 

 chalazal point is consequently identical with the hilar or funi- 

 cular point of attachment of the ovule, and therefore there exists 

 in no case any simple raphe, and but rarely any tracheal vessels, 

 except those which exist in the funiculus : the growth of the 

 ovular tunics is just the same as in the anatropal ovules. Spiral 

 vessels, however, are occasionally seen, extending radially beyond 

 the region of the chalaza, through the tissues of the primine, as 

 sometimes occurs in like manner in anatropal ovules. 



In the foregoing details of an anatropal ovule, I have men- 

 tioned the raphe only as appearing in the shape of a simple cord 

 imbedded in the tissues of the primine, traversing it upon its ven- 

 tral side from the funicle to the chalaza, where it disappears. 

 But other distinct kinds of raphe occur : it frequently happens 

 that, besides the main cord just mentioned, other branches of 

 the nourishing vessels, as they issue from the funicle, spread 

 themselves in distinct nervures over the whole area of the testa : 

 sometimes, as I have shown in the StyracecB, these ramifications 

 are extremely numerous, the delicate spiral threads being loose 

 or in lax bundles, spread throughout the testa, like a fine web ; 

 this also occurs in the testa of Ophiocaryon, Olea, and many other 

 seeds. In other cases, again, we find these ramifications radiating 

 in distinct nervures from the chalaza and anastomosing over the 

 surface of the seed; this is instanced in the Almond, to which 

 Prof. Lindley has alluded as presenting an anomaly not readily 

 accounted for; its nature is, however, easily explained. The 

 Almond is generally described as being exalbuminous ; for if we 

 cut through the seed, we come immediately upon the large 

 fleshy embryo, which is found enveloped by an apparently single 

 flexible coating, but which on examination is seen to be composed 

 of difi*erent integuments agglutinated together. The inner coat- 

 ing is easily detached by a blunt point introduced beneath it, 

 by which means it may be separated entire ; it is then very thin, 

 almost membranaceous, opake, white, not reticulated, but appa- 

 rently formed of minute aggregated cells, and perfectly homo- 

 geneous in all its parts; it is somewhat thickened over the 



