REPORT ON YK'.KTAM.i PABBHENOGEN] !•">•*> 



of individual peculiarities, and oxen of monstrosities, points to the 

 existence nf zoloi \ pieal* reproduct ion, and taJhiequeiM 1\ of partheno- 

 gpneei* lie iIki! nefatrn to fcbe toossea, ma u u intwns that in towq 



<d'ibem male bio* dtft even knuun, whilst in ulhcrs, although 



known, tlicy mrur but seldom, and yet in bojtl LJj iflpcpduqecl 



plenu'fulh . at !< ast in some localities. For example, the male blos- 

 soms of D icran urn undu la In m are entirely unknown, and vet it is a 

 moss whieh forms an abundance ot* fruit." ]n Sphaf/aum moUuscum 

 the male plants are known, but yet the species fruits freely in places 

 where no traee of them is to be found ; and the same tiling occurs in 

 Camptothecium Jutescens. Atrichum un J (datum bears a male ilowcr 

 only in tlie first year ; from whieh, in the second and subsequent years, 

 innovations are produced bearing female flowers. Patches of this moss 

 are often found bearing fruit, but having no first-year male plants in 

 or near them. Fissidens incurvus bears the male flowers at the apex 

 of a lateral innovation of the second year, but it produces fruit in the 

 first year of its growth. Dr. Braun then refers to the Alga?, and 

 dismisses the Vloridea? and Fucoideas as exhibiting no satisfactory 

 proofs of parthenogenesis. He then mentions the Conjugate ; and, 

 adopting Do Bary's theory that the process of copulation is a peculiar 

 modification of sexual reproduction, he considers that the exceptional 

 cases where the spores in the Conjugate are formed without copu- 

 lation must be looked upon as instances of parthenogenesis ; at least, 

 if it may be assumed (what he admits is not yet proved) that such 

 spores agree with the others in their structure and mode of 

 germination. 



In a note at pp. 117 and 118 of his essay, Dr. Braun refers to 

 some experiments of Schenk, made, during the three previous years, 

 in the botanical garden at "Wurzburg, and also to some observations 

 of De Bary made at Freiburg. Schenk directed his attention to 

 Cannabis sativa, Mcrcurialis annua, llicinus' commu/iis, Momordioa 

 elaterium, and Cucurbita Pepo. De Bary speaks of Cannabis saliva 

 alone. Both observers obtained only negative results, and the same 

 was the case with some later observations upon Cannabis satica and 

 Mercurialis made by Schenk, and reported *in the " Wurzburg Nat. 

 Zeitschrift," Bd. 1. pp. 85-89. 



The last publication which we have to mention is Karsien's 

 treatise, entitled " Das Geschleehtsleben der Filanzen und die 

 Parthenogenesis," published at Berlin in LSOO. II that 



anthers are not unfrequently developed -at the base of the <al\ \ q$ 

 the female flowers of Cceleboqt/nc ; that lie has himself observed this 

 in the botanical garden at Berlin ; that if Cwlebogyae be carefully 



* " Zelotvpie" and " Idiotypic" are words coincl by Radlkofcr in his treatise 

 on the relation of partheno^em.'sis to other modes of reproduction. In sexual re- 

 production, the new individual, although retaining the peculiarities of the species, 

 may vary to some extent from the original type. This is called l>y Radlkofcr 

 " idiotypical" reproduction. In asexual reproduction, the now individual is, so to 

 speak, a copy of the old one : this Kadlkofcr calls ' /clotypieal " reproduction. 

 VOL. I. — N. II. E. 3 JN' 



