of the External Coatings of Seeds. 



359 



so that the term anatropal has, in fact, been 

 erroneously applied to it, in consequence of a 

 misconception that has originated in the want of 

 attention to the manner in which this mechani- 

 cal process of growth is effected. By this beau- 

 tiful and most simple contrivance of Nature, the 

 apex of the nucleus is brought into close prox- 

 imity to the orifices of the stigmatic channels, 

 there to receive the pollinic influence held to be 

 essential to the generation of the embryo, prior 

 to the final closing of the orifices of the surround- 

 ing tunics over it. Subsequently the mouth of 

 the extraneous pouch of the placentary sheath 

 also closes up, and this pouch then assumes the 

 form of an entire coating, as in Magnolia^ or it 

 occasionally remains pervious, as in Euonymus-, 

 but we invariably find the nourishing vessels 

 imbedded within its tissues. In ordinary cases 

 these vessels remain as one continuous cord, 

 similar to that first generated within the sheath 

 terminating in the chalazal point, and thus con- 

 stituting a simple raphe; but in others, like 

 that of the Almond, they divide and spread 

 themselves over the whole breadth of the tissues 

 of the pouch, and form at length a branching 

 raphe. By such simple means all the phseno- 

 mena attendant upon what is called anatropal 

 inversion are fully understood and explained; 

 and we are thus relieved from the necessity of 

 imagining the more complicated action of the 

 twisting of the ovule round its funicle, and the 

 paradoxical circumstance assumed to take place, 

 of the insinuation of the nourishing vessels into 

 the tissues of the original tunics of the nucleus ; 

 for it is clear to me, that all the objections I 

 have urged [ante, p. 278) hold good on the 

 assumption generally entertained that the ovule 

 inverts itself, and that in this action its apex is turned round to 

 the point where its base formerly stood, and vice versa; the con- 

 sequence of which is the production of the raphe upon one of 

 its sides. These objections, however, entirely disappear under 

 the view of the actual circumstances that occur in the manner 

 here shown. 



Under this point of view, it is clear that the presence of a 

 raphe, whether as a simple cord, or in a branched state, within 

 the tissues of a seminal coat, indicates with certainty that such 



