8fi MR. MIERS ON THE OUTER FLESHY COVERING OF THE SEED 



the seed, its outer portion forming the pulpy, the inner the crustaceous seed-coat." This 

 ingenious reasoning cannot however be maintained in view of the real cu-cunistances of 

 the case, for it docs not in any degree remove the insuperable obstacle which I have urged 

 against his doctrine, in the position of the raphe ynth. regard to the several coatings of the 

 seed and to the true chalaza. But supposing, for argument's sake, we waive that objection, 

 the reasoning is not tenable upon other grounds, because if such were the origia of these 

 two envelopes, there ought to exist an intimate union of the fleshy exterior with the bony 

 nut, having its several osseous and fleshy deposits enclosed mthin the two original epi- 

 dermal pellicles of the primiae. We find, on the contrary, that the osseous substance of 

 the nut is furnished internally with a smooth skin, and externally with a distinct hardened 

 epidei-mis, which in Talauma I found to be black and polished in the Living state ; the 

 fleshy coating is also furnished on both surfaces with a distinct reticulated membrane, the 

 inner pellicle being clearly seen with a lens. The arilliform coating, in every case exa- 

 mined, I have found provided with a double (that is an endodermal as well as an epi- 

 dermal) membrane, showing it to be a distinct formation from the testa. Although 

 perfectly free from the latter ia Tassijlora, &c., it is generally more or less adherent to it, 

 especially ia those cases where the raphe is spread over its whole area in branching rami- 

 fications : by its close adhesion to the testa, it then forms a compound tunic, and when 

 the external coating is fleshy and the raphe is simple, as in Magnolia, &c., it can often be 

 easily separated from it in an entire state : this is what Gaertner caUs, a baccate or fleshy 

 testa*. 



My view of the nature of this development is simply the following : that ia the act 

 of inversion of the ovule, the spiral vessels destined for its nourishment and always 

 retaining their original attachment to it at the gangylode, are drawn out, together with 

 an enveloping portion of the placenta, so that by means of these spiral vessels and this 

 placentary sheath, the same communication between the placenta and the gangylode of 

 the ovule is maintained that had existed prior to the act of its inversion. This placentary 

 sheath with its enclosed spiral vessels, ai:)pears like a prominent broad external band, as 

 sliown and figured by Dr. Asa Gray, both in relief and in section, in his analysis of Mag- 

 i/olia, to which I have referred : up to this point we are both ia accord. This band 

 afterwards becomes expanded by almost imperceptible degrees over the primine, until it 

 finally envelopes it in the manner I shall presently demonstrate : it then becomes thick- 

 ened by internal deposits, and assumes the form of a distinct scarlet fleshy covering over 

 the testa, being quite arUliform in its structm"e and appearance. The testa is a distinct 

 development, formed by the secretion of transverse crystalline cells, closely compacted 

 within the substance of the primine, the deposition of which cells has been noticed and 

 recorded by Dr. Grayf. The only cu'cximstance that bears any weight in the opposite 



* " Testa carnosa solis competit seminibns baccatis, et respectu situs sui nonnunquam exceptionem a regula facit, 

 cum sEepe tertium a nucleo inter integumenta teneat locum ; ut in Bixit atque Maynolid. Hinc proximam cum arillo 

 habet affiuitatem, atque hac sola nota ab eo discemitur, quod carnosa testa semper arctissimo nexu cum tota seminis 

 sui supprficie cobsereat : ut in mod6 dictis, nee non in Gloriosd, &c., in quibus nullum inter camera atque semen ipsum 

 intereedit spatium liberum, sicut in seminibus arillatis Sci/talice {Nephelii) et aliarum." — Gaertn. Introd. p. 133. 



t Hooker's Kew Joum. Bot. vol. viii. p. 23. 



