DIPSACE.^ 87 



(fig. 454, D). The cotyledons are oval-oblong and shortly 

 petiolate. The first four pairs of leaves vary from spathulate 

 to oblong or elliptic, while the fifth to the seventh pairs 

 inclusive are pinnatipartite. The lamina of the involucel is 

 smaller than in S. palaestina, but there are no perforations in 

 any part of it. The radicle easily pushes its way through the 

 membranous portions at the sides between the greatly thick- 

 ened ribs of the involucel, thus demonstrating the economy of 

 the unequal thickening. A peculiar anomaly presents itself 

 in the germinating seedling of Scabiosa caucasica (fig. 455). 

 The base of the hypocotyl is more or less thickened as in 

 the other species, but it generally if not always pushes itself 

 right through one or other of the membranous portions of 

 the involucel, and the thickening appears therefore to be now 

 functionless so far as its original purpose is concerned. The 

 lamina of the involucel is reduced to a rim crowned by numerous 

 coarse bristle-like segments. The seedling is different from all 

 others I have noticed. The hypocotyl remains short, the oblong 

 entire cotyledons are sessile, and the first pair of leaves are 

 oblanceolate and entire. The radical leaves of the adult plant 

 are spathulate, entire and decurrent upon the long petiole, but 

 most of the cauline ones are pinnatisect with linear segments. 



The seedlings of S. rutaefolia (fig. 456) exhibit a similar 

 evolution of the foliage to S. atropurpurea, but I have not 

 seen either the fruit or germination. Furthermore the seed- 

 lings are dimorphic ; some have opposite leaves with the first 

 three pairs spathulate and bluntly serrated near the apex, 

 and the fourth pair more or less lobed, while others have 

 the leaves in whorls of three. Those of the first three whorls 

 resemble the leaves of the first type, but in the fourth 

 and fifth whorls they are irregularly and deeply pinnatifid. 

 The cotyledons of S. maritima are obovate-oblong and emar- 

 ginate, while the first pair of leaves are oval or obovate. 



It will be noticed that in all of the above-mentioned seed- 

 lings the cotyledons are sessile on leaving the seed, but after- 

 wards petiolate, Scabiosa caucasica alone forming an exception. 



Dipsacus sylvestris, L. 



Fruit an achene enclosed in a tetragonal involucel, having an 

 intermediate set of smaller ridges, one on each face, free from the 



