20-A Br. L. lladlkofer on true Parthenogenesis in Plants, 



XXII. — On ti-ue Parthenogenesis in Plants. ' « 



^joT:v%!i«.v By Dr. L. IUdlkofer, of Munich*. ^qaarfo 



It would indeed be difficult to find anywhere a more evident 

 proof of the imperfection of human knowledge than is furnished 

 by the contradictory results of the latest embryological investi- 

 gation, in the departments of zoology as well as of botany. If 

 our knowledge of the process of fecundation in animals appear 

 to have made an important step forward through the observation 

 of the penetration of the spermatozoids into the ovum, — if this 

 seemed to put beyond all doubt the material participation of the 

 spermatozoids in the formation of the embryo, — we must be 

 doubly surprised by the observation, that in particular — appa- 

 rently determinate — cases, the formation of the embryo occurs 

 without any cooperation of the spermatozoids, therefore without 

 previous fecundation of the ovum. This true Parthenogenesis, 

 demonstrated with all the exactness which science can require 

 by Prof. Von Sieboldf, in the Lepidoptera, and in the Bees 

 particularly, is paralleled by analogous cases in the neighbouring 

 domain of plants. 



J In calling the attention of zoologists for a moment to an 

 SHBCount of them, I have a twofold purpose : to convince those 

 still in doubt by the number of proofs, and to attract to the 

 subject itself as many observers as possible. 



Embryological researches in the vegetable kingdom have kept 

 pace with those in the department of zoology. Analogues of 

 the animal ovum, analogues of the animal fecundating matter, 

 have been demonstrated in all groups of the vegetable kingdom, 

 with the exception of the Fungi and Lichens. 



To the ovum corresponds the germ-vesicle of the Phanerd- 

 gamia, of the llhizocarpese, Equisetacese, Ferns and Mosses'; 

 and, besides this, the primordial spore- cell of the Algje. The 

 germ-vesicle (vegetable ovum) presents itself as a perfect cell, 

 furnished with a membrane and a cytoblastj; in the Algae we 

 find, instead of the perfect cell, one devoid of a membrane, an 

 ovum without an integument, — the naked primordial spore-cell. 



To the spermatozoids contained in the spermatic fluid of ani- 

 mals, the material basis of which we must regard, according to 



* Translated from Siebold and Kolliker's Zeitschrift, viii. Heft 4(1857), 

 by Arthur Henfrey, F.R.S. &c. 



t True Parthenogenesis in Moths and Bees, &c. By C. Th. Von Siebold. 

 Translated by W. S. Dallas, F.L.S. London, Van Voorst, 185/. 



X We dissent from the author on this point, believing that the iinim- 

 pregnated germ-cell has not yet a cellulose membrane, but resembles the 

 unimpregnated 8|K)re of Fucus. See Annals of Nut. Hist. 2ud scr. xviii. 

 p. 21 7 (Sept. I85fi).— [A. II.] 



