44 On the Affinities of Cerxttophyllacea. 



of being the only remarks extant which throw any light upon 

 the true aifinities of Ceratophyllum, have also the misfortune of 

 having been wholly overlooked by succeeding systematic 

 writers. Under these circumstances it is proper to quote that 

 portion of the observations of M. Brongniart which have a di- 

 rect bearing upon the subject under consideration. They re- 

 late, in part, to a remarkable peculiarity in the developement 

 of the embryo of Ceratophyllum, which is also inferred to 

 occur in the genus Nelumbium. 



" Si on examine 1' ovule du Ceratophyllum demcrsum au mo- 

 ment de la floraison, on trouve qu'il est suspendu au sommet 

 de la cavite de l'ovaire, et qu'il est compose" d'un seul tegu- 

 ment ouvcrt a Vextremite opposed a son point d'insertion ; l'a- 

 mande e"galement suspendue est formed d'une membrane cel- 

 luleuse, mince, transparente, et se termine par un mamelon 

 court, form6 par une sorte de petite couronne de cellules. 

 Dans Pinterieur de cette amande, ou trouve le sac embryon- 

 naire (the tercine of Mirbel ?) qui la remplit en entier ; il est. 

 fixe" superieurement a la chalaze,"* &c. The passage above 

 quoted suffices to show that M. Brongniart considers the ovule 

 of Ceratophyllum as suspended and orthotropous, and 

 the accompanying figurest so represent it. The author 

 proceeds with an account of the embryo at its first develope- 

 ment, when it appears as a minute green globule, situated, not 

 within the nucule, but outside of it, and merely in contact with 

 its orifice, from which the slightest force suffices to detach it. 



" II continue a s'accroitre pendant quelque temps en adh6- 

 rant I6ge>ement a l'extre'mite' du sac embryonnaire ; rnais 

 beintot il s'en degage et se dcveloppe dans la cavite" comprise 

 entre la membrane de l'amande et ce sac ; il se divise en trois 

 lobes, les deux lateraux se prolongent sous forme de cornes 



» Ann. Sciences Naturelles, 12, p. 251, et scq. 

 f Op. eit t. 44. 





