and its relation to that in the Animal Kingdom. 253 



Thus the matter rested for more than fifty years, until know- 

 ledge took the place of conjecture. Pringsheim* it was who 

 made the matter clear by the direct observation of the act of 

 fecundation in Vaucheria sessilis. While other phycologists 

 believed in a conjugation of the horn with the sporange standing 

 besidef it, and KarstenJ thought that he discovered a process 

 of fecundation by the emission from the horn of a cell containing 

 formative matter (which he compared with the pollen-cell, as 

 supposed to be efficient on Schleiden^s former hypothesis), which 

 united, together with its membrane, with a germ-sac-cell con- 

 tained in the sporange, and thus became a productive {entwick- 

 lungsfdhig) germ or spore, — Pringsheim saw the terminal cell of 

 the horn open at its point and emit a great number of minute, 

 bacillar corpuscles — spermatozoids, which slipped away in all 

 directions with a rapid motion. Many of them crowded into 

 the orifice already formed in the beak-like apex of the spo- 

 range by the pressure of its accumulated protoplasm — into the 

 micropyle of the sporange, and appeared partly to penetrate into 

 the protoplasm itself. Immediately upon this, the protoplasm 

 became enveloped by a new cell-membrane, 8lnd thus appeared 

 as a complete resting- spore, completely filling the sporange. 

 The formation of the horn — the antheridium, as well as that of 

 the sporange, takes place by a papilla-like bulging-out of the 

 wall of the tubular cell of Vaucheria, such as happens in the 

 ordinary ramification, and a subsequent separation of its cavity 

 from that of the general filament of the Alga, by a septum. The 

 sporange remains as a simple cell, until the time of the forma- 

 tion of the spore ; the curved, tendril-like antheridium is divided 

 by a cross-septum into two superposed cells before it is mature. 



In May of last year I had an opportunity of making confirm- 

 atory observations on this important discovery of Pringsheim^s, 

 which at once throws a bright light over the essential nature of 

 the fecundating process in the vegetable kingdom, and fills up a 

 hiatus in the related observations on the higher Cryptogamia. 



Specimens of Vaucheria sessilis, collected in a ditch at Jena, 

 exhibited both perfectly ripe fruits and partly decomposed horns, 

 and, besides these, all the earlier stages of development of the 

 sporange and antheridia, back to the earliest nipple-like pro- 



* N. Pringsheim, Ueber der Befruchtung, &c., der hoheren Algen. 

 Monatsbericht der K. Acad. d. Wiss. BerUn, 1855. (Abridged in Ann. Nat. 

 Hist. 2 ser. xiv. p. 346, &c. Quarterly Journal of Microscop. Science, iv. 

 p. 63.) 



t Vide Nageli, Neuerer Algensystem, &c. Zurich, 1847, p. 175. pi. 4. 

 figs. 21 & 22 ; and A. Braun's doubts as to Nageli's account in liis ' Ver- 

 jiingung,' &c. (Transl. in Ray Society, vol. 1851, p. 296.) 



t II. Karsten, Der Fortpflanzung der Conferva fontinalis, L. Botan. 

 Zeitung, 1862, p. 89. pi. 2. 



