266. OBSERVATIONS ON THE NATURAL FAMILY 



unites with it considerably below its termination. In H. 

 tenuifolius this irregularity is still greater ; one branch being 

 not unfrequently altogether wanting, and even the re- 

 maining branch considerably weakened : where this happens 

 a secondary vessel is always produced, though very few 

 flosculi are furnished with five complete middle nerves. 



To the fact stated by M. Cassini that the lateral nerves 

 are always simple, I have met with only one apparent 

 exception, in an unpublished species of Madia, where they 

 are connected by a few branches with the secondary or 

 84] middle nerve, which in this plant is more strongly 

 marked than the primary, and from which indeed these 

 connecting branches probably originate. 



It must, I think, be admitted by M. Cassini, that in 

 many genera of Compositse five vessels passing through 

 the axes of the segments exist, even ten others are occa- 

 sionally found, as in Helianthus, though these can hardly be 

 traced below the insertion of stamina. But as it has been 

 already shown that the lateral or primary vessels are not 

 strictly marginal through their whole length, and as one 

 instance has been produced in which their branches, if not 

 themselves subdivided, are at least connected by ramifica- 

 tions of the middle nerves,^ it follows that a monopeta- 

 lous corolla having in its tube fifteen nerves with distinct 

 origins, three of which are continued through each of its 

 segments, and unite together at the apex, would upon the 

 whole better correspond with the definition M. Cassini has 

 given of the Corolla of Compositse, than the actual dispo- 

 sition of vessels in that order. Now such a structure 

 exists in the whole of Goodenovise,^ a family of plants very 



' M. Cassini himself (in a note to his third memoir published in the Journal 

 de Physique for February 1816, p. 129) has given another instance of the rami- 

 fication of nerves in Ivafrutescetis. , 



^ I have formerly observed (in Prodr. Flor. Nov. Holl. p. 580, and in General 

 Remarks on the Butany of Terra Australis [vol. i, p. 33]) that Euthales and Velleia, 

 genera belonging to Goodenovia, exhibit the remarkable and nearly peculiar 

 character of a corolla having the lower part of the tube cohering with the ovarium, 

 while the calyx is entirely distinct. I have at the same time remarked that, 

 even in those genera of the same natural family in which the calyx is coherent, 

 the tube of the corolla may be supposed to be continued down to the base of the 

 ovarium ; and that this becomes even evident in such species as have the 



