276 Mr. J. Miers on the Nature and Origin 



XXV. — On the Nature and Origin of the External Coatings of 

 Seeds. By John Miers, E.R.S., F.L.S. &c. 



The above question has not sufficiently attracted the attention 

 of botanists, who have often described the seminal tunics under 

 different appellations, according to their notions of the source of 

 their development ; but, in a paper published nearly two years 

 ago*, I pointed out the test by which, as it appeared to me, 

 their true origin can always with confidence be determined. 

 Dr. Asa Gray has lately presented a paper to the Linnaean Society, 

 in which he maintains the view he first enunciated respecting 

 the seed-coats of Magnolia ; in that paper this eminent botanist 

 details his observations on the development and growth of its 

 ovule, particularly in regard to the period when the osseous 

 deposits are secreted within the primine; from these observa- 

 tions he still contends that the outer fleshy tunic of its seed 

 derives its origin from the primine, and is therefore a portion of 

 its testa. If this doubt were confined solely to the case of 

 Magnolia, it would be of small moment, but as it affects a lead- 

 ing feature in the development of most other seeds, it becomes 

 a question of extensive importance ; and under this impression, 

 as the facts described by my esteemed friend appeared to me to 

 admit of a different solution, I soon after read a paper before 

 the same Society, in which, carefully avoiding all controversial 

 disputation, I briefly confined myself to a revision of the argu- 

 ment, bringing forward other facts and inferences, with a view 

 of resolving the matter. The Council of that Society published 

 Dr. A. Gray's paper, but, in a manner quite inconsistent with 

 the spirit of scientific progress, refused a place to my observa- 

 tions in its Quarterly Journal, on the score that its ' Proceedings' 

 are not a fit medium for contention on this point of science. I 

 am fully aware how difficult it is to establish any novel views of 

 structural development, and as I am desirous, for the cause of 

 truth, that the matter in question should be decided, I submit 

 it to the consideration of botanists, with the hope that they will 

 throw aside for the moment their previous conclusions, and give 

 their unbiassed attention to the facts and arguments here pre- 

 sented to their notice. With this view I will condense into an- 

 other form the bearings of the whole question, introducing first 

 a few premises, the import of which seems to have been lost 

 sight of in this inquiry. 



1 . Vegetable growth in all its stages is regulated by the ordi- 

 nary laws of mechanical action, and hence all inferences from 

 seeming facts, or those often assumed to be facts, which are in- 



* Linn. Trans, xxii. 81. 



