233 . Dr. L. Kny 07i the Structure and 



My own investigations as yet relate only to a few species. 

 Nevertheless, to jiulge from the statements and pictorial re- 

 presentations contained in the literature of the suhjeet, the 

 most important ditferences in the structure of the -anthcridium 

 are represented by tliem. In a short time I hope to he able to 

 complete my observations upon most of the genera of Filices. 

 It scarcely needs to be mentioned that 1 liave not obtained the 

 materials for my investigation from the im])ia'e cultivated 

 forms of the fern-houses, but that the sowings have been made 

 specially for my purposes, and carefully protected from foreign 

 interlopers. 



Aneimia hirfa possesses anthcridia which arc remarkable 

 for their considerable size and simple structure. In the ma- 

 ture state (PI. VI. fig. 5) they consist of a depressed cylindrical 

 stalk cell, a comparatively elevated annular cell set U])on this, 

 in which no indication of a longitudinal septum is visible, and 

 a low opercular cell in the form of the segment of a sphere. 

 The inner cavity enclosed by the three cells is filled by the 

 spedal mother cells of the spennatozoids. 



On Aveakly prothallia growing very close together they 

 spring in about equal abundance from the underside of the 

 leafy surface and from the margin. In the last-mentioned 

 position their development is easily ascertained by the com- 

 parison of different stages. 



The youngest observed rudiments, which scarcely projected 

 as hemispheres above the margin (fig. 1), and in the fresh 

 state appeared to be uniformly filled with turbid protoplasm, 

 proved, on closer examination, to be not only separated from 

 the marginal cell liy a septum, but even already to consist of 

 three cells. The lower, peduncular cell, which is greatly 

 curved iuAvards, is bounded by two parallel Avails, of Avhich 

 the superior is the youngest. Upon this follows a watch- 

 glass-shaped sc])tum curved outAvards in a circle concentric 

 Avith the peri])heral boundary of the peduncular cell, cutting 

 off an inner cell of the form of a bicouA^cx lens from a shalloAv 

 bell-shaped cell Avhich covers it. Whilst the peduncular cell 

 scarcely becomes perceptibly elongated, the tAvo other cells 

 both become strongly arched outwards. At the same time the 

 sc])tum se])arating them long remains A'ery delicate, so that it 

 eludes direct observation (fig. 2 a) ; Avhen the prothallium is 

 treated Avitli solution of potash and muriatic acid, it makes its 

 appearance quite distinctly (fig. 2Z*). About the time AAdien 

 the inner cell has acquired a hemispherical form, there is ]n-o- 

 duced in the bell-shaped cell coAxring it a iimnel-shajjed 

 septum Avidening upAA^ards, Avhicli is a^jplicd both to the inner 

 and outer Avail, in a closed circle. Its formation appears to be 



