16 Mr. J. Miers on the Development 



this celebrated memoir can we find any material variation in the 

 direction of the parts of an anatropal ovule : this only exists in 

 campylotropal or amphitropal ovules, where, of course, owing to 

 the curvature of the several parts, from an excessive one-sided 

 growth, a more or less partial inversion takes place. 



The same erroneous description is given by the able St.-Hilaire 

 in his ' Morphologic Vegetale ' (p. 540), where he thus defines 

 the development of an anatropal ovule. Its first appearance 

 upon the placenta is a small protuberance (wrongly said to be 

 the nucleus of the future ovule), which by degrees becomes co- 

 vered by two cups that rise successively from its base and form 

 the future tunics, primine and secundine. The so-called " ovules 

 anatropes, par la courbure graduelle de la base de leur axe, se 

 rapprochent peu k peu du cordon ombilical, et apres avoir decrit 

 un demi'Cercle, le rencontrent, se soudent avec lui, et le confondent 

 en quelque sorte dans leur substance j souvent le cordon, ainsi 

 soude, se montre comme une proeminence exterieure, mais sou- 

 vent aussi il ne se laisse point apercevoir ; la partie soudee du cor- 

 don porte le nom raphe." In order to impress this action more 

 forcibly upon the conviction of his readers, St.-Hilaire compares 

 the ovule so developed, to a monopetalous flower in bud, which 

 is made to perform half a revolution, by being inverted and 

 suddenly bent down close to its base, with its peduncle aggluti- 

 nated to the calyx and corolla ; here the calyx and corolla assume 

 the position of the tunics of the ovule — its ovary, the nucleus — 

 and their common base of union, the chalaza, — the pedicel 

 representing the raphe. 



A very similar explanation of the anatropy of the ovule is 

 given in the excellent work of Adr. de Jussieu (Cours Clemen - 

 mentaire, p. 343), where his definition is aided by figures. 

 Fig. 1 is again erroneously said to be the nucleus, first developed-, 

 fig. 2 the same, with the primine next appearing ; fig. 3 the same, 

 more advanced, with the addition of the second coat (secundine). 

 "Le developpement ne marche pas ainsi ^gal de tons les cotes ; sur 

 Vun il est tres-prononce, tandis qu^il reste k peu pres stationnaire 

 sur le cote oppose. Par \\ la pointe de Povule, avec son micro- 

 pyle tourne primitivement en haut, se tourne de cote, puis un peu 

 plus tard en dehors, puis enfin tout a fait en bas (fig. 4) apres 

 avoir fait ainsi un demi-tour de revolution. La chalaze emportee 

 de meme avec les tegumens qui s'etendent, et conservant ses 

 rapports avec le micropyle, fait une revolution analogue, mais en 

 sens inverse, et marche de bas en haut, de maniere qu^elle s'eloigne 

 de plus en plus du hile, dont le micropyle au contraire s'est 

 rapproche de plus en plus." Fig. 5 shows a section of the same 

 ovule, where it is explained how "le faisceau vasculaire qui 

 aboutissait h la chalaze, la suit dans sa revolution en s'allongeant, 



