302 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 54 



that the latter, instead of having both kinds of flowers, the fertile 

 and small and the sterile and showy, has but the sterile kind. 

 Plainly, he regards it as but a freak, a variety of the other. It is 

 also worth noting that his is the earliest mention in history of thig 

 universal favorite, which he says grows wild along with the other, 

 but is rare, except in gardens and pleasure grounds to which they 

 transferred it from its native wilds. ^ 



The question of the degree of relationship subsisting between 

 the two kinds of Dipsacus, or teasel, has exercised the minds of 

 successive generations of taxonomists early and late. Cordus 

 appears to have settled it at the outset in the right way; or at 

 least in a manner to satisfy the requirements of the m.odern evolu- 

 tionary. He almost fills a folio page with his fine description of 

 the original wild and useless D. silvestris, and then disposes of the 

 cultivated and singularly useful D. sativus in five lines; even these 

 five relating in the main to the mechanical serviceability of the 

 hard, prickly heads; presenting as the only morphological distinc- 

 tion between this and the former, the harder, firmer texture and 

 convenient curvature of the prickle-like bracts investing the head.^ 



A philosophic botanist, writing for the philosophic, need not 

 more explicitly avow his belief that Dipsacus sativus is but a 

 usefully variant offspring of Dipsacus silvestris; nor need he more 

 clearly express his understanding that the wild thing, being the 

 type of the species, is the thing for the botanist to describe in full. 



Illustrations have been given already of Cordus' superior skill 

 in bringing into line related genera, as if members of a natural 

 family; but these taxonomic notes must not be concluded without 

 allusion to one of the most striking manifestations of his ability to 

 segregate, amend, and improve larger groups. Perhaps the best 

 example of all is one that occurs in his early lectures on Dioscorides. 

 The pharmacists of the time have a group of plants which they 

 know as the Lactariae, that is, milky-juiced herbs. Those best 

 informed understand the species of the euphorbiaceous genus Tithy- 

 malus to be meant by this name Lactariae, so says the lecturer; but 

 then, he adds the suggestion that so many other herbs besides these 

 have the faculty of shedding drops of milky juice when their stems 

 are cut or broken, and the milks of these different herbs are so dis- 

 similar as to their properties— some being innocuous, others poison- 

 ous—that the plants ought clearly to be distinguished in, groups. 



' Hist. PI., p. 190. 



2 On the history of the Dipsacus controversy, and its nomenclature, cf. 

 Greene, Pittonia, vol. iii, pp. 1-9. 



