of individual peculiarities, and even of monstrosities, points to the existence of zelotypical[1] reproduction, and consequently of parthenogenesis. He then refers to the mosses, and mentions that in some them male blossoms are not even known, whilst in others, although known, they occur but seldom, and yet in both cases fruit is produced plentifully, at least in some localities. For example, the male blossoms of Dicranum undulatum are entirely unknown, and yet it is a moss which forms an abundance of fruit. In Sphagnum molluscum the male plants are known, but yet the species fruits freely in places where no trace of them is to be found; and the same thing occurs in Camptothecium lutescens. Alrichum undulatum bears a male flower only in the first year; from which, 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 Algæ, and dismisses the Vlorideæ and Fucoideæ as exhibiting no satisfactory proofs of parthenogenesis. He then mentions the Conjugate; and, adopting De 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 copulation 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, Mercurialis annua, Ricinus communis, Momordica elaterium, and Cucurbita Pepo. De Bary speaks of Cannabis sativa alone. Both observers obtained only negative results, and the same was the case with some later observations upon Cannabis sativa 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 Karsten's treatise, entitled "Das Geschlechtsleben der Pflanzen und die Parthenogenesis," published at Berlin in 1860. He asserts that anthers are not unfrequently developed at the base of the calyx of the female flowers of Cœleboqyne; thathie has himself observed this in the botanical garden at Berlin; that if Cœlebogyne be carefully
- ↑ "Zelotypie" and "Idiotypie" are words coined by Radlkofer in his treatise on the relation of parthenogensis to other modes of reproduction. In sexual reproduction, the new individual, although retaining the peculiarities of the species, may vary to some extent from the original type. This is called by Radlkofer "idiotypical" reproduction. In asexual reproduction, the now individual is, so to speak, a copy of the old one: this Radlkofer calls "zelotypical " reproduction.
