94 MR. MIERS ON THE OUTER FLESHY COVERING OF THE SEED 



Byania (Fatrisia), as shown in Delessert's ' Icones,' iii. tab. 14, the seed is covered by a 

 similar arilline, and along the whole length of a similar longitudinal raphe, a lateral 

 cupular fleshy expansion is developed, manifesting the coexistence of aril and arilline, 

 emanating from the same origin. Both these developments also occur in Paropsia, 

 where the seeds are suspended by a long funicle, which, at the hHum, is expanded into 

 a fleshy cup, that envelox^es the lower half of the seed. In Acharia the longitudinal 

 raphe becomes distended on each side, forming a lateral gibbous process (Ann. Nat. Hist, 

 iii. pi. 9. fig. 15) analogous to that before referred to in Asarum. In Modecca palmata 

 an entii'e and very thick fleshy tunic invests the osseous testa, marked by a prominent 

 longitudinal keel, enclosing the raphe (Wight, ' Icon.' tab. 201. fig. 12, 13, 14, &c.), and 

 in Modecca Wightiana (id. tab. 179. fig. 3) we see precisely the same development, -with 

 the addition of another crenated hemispherical fleshy cup, covering the base of the seed. 

 This is also seen in Modecca australis (Endl. ' Icon.' tab. 115). In aU these cases, the 

 raphe is perfectly free from the testa, and always forms part of a more external tunic 

 more or less adherent to it, the arilliform natm-e of which has never been doubted ; the 

 structure is quite analogous to that found in Magnolia, &c., and distinct &om the still 

 more external development, the true arU. 



The mass of evidence here adduced, strengthened by the observations of botanists of 

 high repute, showing the nature of the several metamorphoses which accompany the pro- 

 duction of the raphe under its different forms, indicate the real placentary origin, whether 

 mediate or immediate, and therefore the arilliform character of the several extraneous 

 tunics, which assume such various textures and conditions around the testa, — restricting 

 this latter term within the limit usually assigned to it — a simple development and growth 

 of the primine of the ovule. The question appears to me so simple and manifest, that I 

 sliould have considered it unnecessary to enter into such full details in its support, if this 

 point of structure had not been so positively denied by the high authorities to which 

 I have referred : a desire for the solution of the truth has alone induced me to extend 

 these observations to a greater length than otherwise would have been requisite. Many 

 other interesting topics of physiological inquiry are connected with the farther considera- 

 tion of this subject, and I have prepared another paper, in which are discussed many of 

 the phsenomena attendant on the peculiar direction of the raphe, especially in reference to 

 the anomalies before alluded to, in Stemonurus, Anona, the Cucurbitacece, and other 

 instances, with a view of tracing the causes of such unusual deviations from the ordinary 

 course of structure. 



