154 Mr. J. Miers on the Bignoniaceae. 



have been made since that time : among these may be mentioned 

 those of Dr. Seemann on the Crescentiacea and some of the 

 genera of the Catalpea : the attention of the same botanist has 

 also been for some time directed to the study of the family ; and 

 it is to be hoped that he will publish the results of his investiga- 

 tions. 



The order is divided by DeCandolle into two tribes, distin- 

 guished in great measure by the presence or absence of winged 

 margins to the seeds : in the former case {Bignoniem) the fruit 

 is capsular and dehiscent, with winged seeds ; in the latter case 

 (Crescentiece) it is either fleshy or ligneous and indehiscent, with 

 apterous seeds, often imbedded in pulp. I have already pointed 

 out, in the former tribe, the anomalous instance of Oxycladus *, 

 where the fruit is an indehiscent mit, normally 2-locular and 

 pluriovular, but by abortion unilocular and monospermous, the 

 seed being perfectly apterous, with two thick fleshy cotyledons 

 conjoined by a very small terminal radicle. I indicated also an- 

 other instance in Adenocali/mnaf, where, although the fruit is 

 capsular and dehiscent, the seeds have no wings, their integu- 

 ments b^ing coriaceous and hard, and theii'cotyledons very thick 

 and fleshy. In Platycarpum and Henriquezia the seeds are like- 

 wise fleshy and wingless. In Argylia, also, some species have the 

 seeds quite apterous, in others the wing is only rudimentary. 

 Thus it appears that this feature is not sufficiently constant to 

 serve as a basis for tribual distinction. I propose in the follow- 

 ing remarks to search for other characters ; and with this view I 

 will first notice several modifications I have observed in the 

 structure of the seeds, and then inquire into the modes in which 

 the carpels are combined. 



In the BignoniecE the seed usually consists of a coating, con- 

 siderably flattened, with a coriaceous centre surrounded by a 

 broad, delicately membranaceous wing, generally broader than 

 long : it has no funicle, but near the margin of the coriaceous 

 portion, contiguous to its base, a small linear hilum is seen, 

 which corresponds with a similar cicatrix on the dissepiment, 

 where it was attached. As an example of the general structure 

 of the seed in the Bignoniece, we may take that of Pithecoctenium 

 squalus. Here it is surrounded by a very broad wing, of extreme 

 tenuity, dehcately reticulated, perfectly hyaline, with a number 

 of strong nervures radiating from the coriaceous discoidal centre. 

 After sufficient maceration, it is easy to introduce a blunt needle 

 into the substance of the wing, when it can be separated into two 

 very distinct laminse, even to the utmost margin, proving that the 

 wing, although in this case of extreme tenuity, is not a simple 



* Linn. Trans, xxi. 145; Linn. Proc. ii. 270. 

 t Linn. Proc. ii. 272. 



