404 On Parthenogenesis. 



a 



impregnated, would Lave produced females, will, if no spermatozoa are 

 present, give birtli to males.* 



"Several naturalists have convinced themselves that some plants have 

 also the power of producing agamic seeds, and Gsertner has given an 

 abridged account of the experiments on^the subject, 



*'The plants in which the most complete experiments have been under- 

 taken, and in which agamic seeds are supposed to have been obtained, 

 are as follows ; — 



■ Zea mays^ by R. J. Camerer, and again by Henschel ; Cannabis sativa^ 

 by Spallanzani, Henschel, Giron de Buzareingues, Bernardi; Spinacia 

 oUracea^ by Spallanzani, Henschel, Giron de Buzareingues ; Cucurhita 

 melopepo, Spallanzani ; Cucurhita CitrulluSj Spallanzani ; Coj/x Lacryjaa^ 

 Henschel ; Lychnis dioica^ Henschel, Giron de Buzareingues ; Mercurialis 

 annna^ Ramisch, 



" Gsertner, however, is inclined to doubt the truth of the results ob- 

 tained, and to ascribe the supposed agamic fertility either to pollen brought 

 from a distance in the air, to the unnoticed presence of male flowers, or 

 to *crypto-hermaphroditism.' Mr. Smith, Curator of the Royal Kew 

 Gardens, mentions a case of seeds which germinated without any appa- 

 rent action of pollen as occurring in Cadehogyne ilicifolia^ a native of 

 Moreton Bay, and belonging to the Euphorbiacese, which was introduced 

 into this country by Mr. Cunningham, who sent three plants to the Kew 

 Gardens in 1829. 



^' These plants produced female flowers from which perfect seeds have 

 been obtained for several successive years, although Mr. Smith could never 

 detect 'anything like male flowers or pollen-bearing organs:' the ovarium 

 and the seeds presented 'the usual structure of Euphorbiaceae, such as it 

 occurs in Croton^ Phyllanthus^ Cluytia^ <fcc.'f 



" Still more recently,^ M. Henri Lehocqhas observed the same phenom- 



enon. He says, 'Mes experiences out ete faites sur le chauvre, Tcpinard, 

 ]e Mercurialis annua, le Trinia vulgaris^ le Lychnis syhestris^ et sur une 

 Cucurbitacee dont j^ignorais le nom specifique. Je n'ai pas besoin de 

 rappeler que j'avais pris toutes les precautions possibles pour isoler mes 

 plantes, et cependant, a rexception du Cucurbitacee et du Lychnis, toutes 

 les autres me donnerent des graines fertiles.'^ 



"Dr. Carpenter,! and after him many authors, as for instance Br. Bur- 

 nett,^ Cams,** and M. do Quatrefages, have sustained wnth ability the 

 theory that the specimens which produce the so-called internal buds or 

 gemmae are not females, but entirely without sex. Thus, M. de Qautre- 

 fagesff says, * Toutes les generations intermediairies developpees entre les 

 termes extremes de ce cycle sont agames, c'cst a dire, manquent de ven- 

 tebles organes reproducteui^, et so raultiplient exclusivement par bouture 

 et par bourgeon interne on externe.' 



"These and similar assertions, however true with reference to the 

 Zoophytes, require great modifications with regard to the x\rticulata. 



Walire Parthenogenesis, &c,,pasnm. 

 t See Transactions of the Linnean Society, vol. xviii, p. 609. 

 X Comptes Rendus de T Academic des Sciences, 8 Dec. 1866. 

 S See also Journal of Microscopical Science, July, 1857, p. 228. 



X. c. p. 443. ^ L, c. p. 9S. ^^ L. c. \\ L c, p. U©. 



