^ESTIVATION AND ITS TERMINOLOGY. 187 



claim, obvoluta will be the proper term, beginning as it did 

 with Linnaeus for vernation, and taken up, as it was very 

 early, by Mirbel for aestivation. The only objections to it 

 are, first, that it has never come into systematic use, and, sec- 

 ond, that 06, in the composition of botanical terms, commonly 

 stands for obversely or inversely. But obvoluta is not bur- 

 dened with this signification : it is classical for " wrapped 

 round," as is convoluta for rolled together. I conclude that 

 one or the other of these two terms ought to be used. 



Finally, although there is little, if any, practical misuse, 

 there is some mis-definition, of the term imbricate as applied 

 to aestivation. Adrien de Jussieu defines it well (in Cours 

 Elementaire, 308) in the phrase "La prefloraison spirale est 

 aussi nomme imbriquee " ; and in noting that when the num- 

 ber stops at five, the pieces fall into two exterior, two interior, 

 and one (the third in the spiral) intermediate, this making 

 what is called " aestivatio quincuncialis." * This is clear and 

 to the point. But other authors have had a fancy for distin- 

 guishing between quincuncial and imbricate (as if the former 

 were not the typical case of the latter when the parts are five), 

 and so have had to devise something else to answer to imbri- 

 cate. Alphonse De Candolle (in his Introd. Bot., i. 154, 

 written before phyllotaxy was well understood), after rele- 

 gating imbricative to the category of a crowd of verticils, 

 and remarking that the quincuncial is sometimes confounded 

 with the imbricate, adds that some confound also under this 

 latter name the case in which there is one exterior piece, one 

 interior, and three covered at one margin but free at the other. 

 I know not where this began ; but its latest reproduction is in 

 Le Maout and Decaisne's " Traite" Generale " and in the Eng- 

 lish translation of it. In the diagram the pieces are numbered 

 directly round the circle from 1 to 5, the fifth coming next 

 the first : " so they thus complete one turn of a spiral," — 

 which shows that Le Maout had vague ideas of phyllotaxy, of 



1 The name quincuncial answers the purpose after definition, and has 

 long been in use ; but this arrangement in diagram is wholly unlike the 

 quincunx, with its four pieces or stars in the periphery, or at the angles 

 of a square, and one in the centre. 



