122 ANATOMY AND PHYSIOLOGY OF 



cells l-900tli of line in diameter, -with a scarcely visible spiral filament 

 within ; but it maj l)e permitted, considering tlie difficulty wbicb bucli 

 minute size of the organ opposes to observation, to doubt, with Mette- 

 nius, whether there are really seminal filaments.^ 



The uniformity of the seminal filaments contained in the an~ 

 theridia of the leafy Cryptogamia, leaves no doubt, in spite of the 

 difierence of structure as above described, that these organs are 

 of the same physiological nature. The circumstance, however, that 

 these organs present themselves at such different stages of deve- 

 lopment of the plants, must appear in the highest degree surpris- 

 ing and indicative of altogether unlooked-for differences in the 

 propagation of these vegetables. From the study of the Phanero- 

 gamia, we are accustomed to regard the organs of fructification as 

 the last stage of vegetable development, since their formation puts 

 a period to any growth of the vegetative axis, and the maturation 

 of the seed frequently involves the death of the parent organism. 

 We meet with the same condition in the Mosses, in which the an- 

 theridia and the rudiments of the sporangia are developed at the 

 same time, the full development of the fruit succeeding the ripen- 

 ing of the anthers. In the Ferns, on the contrary, the condition 

 is diametrically reversed. The development of the sporangia fol- 

 lows the usual law, but the formation of the antheridia takes place 

 upon the pro-embryo after the spores have geiminated, never to 

 be repeated in the plant growing up from the pro-embryo. In the 

 Ehizocarpese, finally, the cells which enclose the seminal filaments 

 are first developed after the pollen-grains (small spores) have been 

 shed ; they are as it were dioecious plants, in which only the fe- 

 male plant arrives at pei^fect development, the male being arrested 

 at the stage of a germinating pollen-grain, which only produces 

 seminal cells, and then dies. 



Before I pass to the consideration of the female organs of fructi 

 fication of these plants, it will be necessary to speak of the spores 

 and their development. 



I have already indicated that the spores of the higher Crypto- 

 gamia agree completely with the pollen-grains of the Phanero- 

 gamia in resjard to their development and structure. Not only 

 m a portion of the Cryptogamic families, namely in the Equise- 

 tacese, Ferns, and Lycopodiacese, does the sporangium fully agree 

 with the theca of an anther in morphological respects (" Morph 

 BetracM, des Sporang, d. ^m. Oefdss^ verseh Kryptog.^' — Mohl 

 " Verm SchHft/' 94), but the development of the four spores in a 

 parent-cell, and their structure, as has been more minutely pointed 

 out above, are completely in agreement with the development and 



* The recent observations seem to indicate the existence of sexes in the 

 Lichens, (^' Itsigsohn'' — JBot. Zdt 1850,51), and the 'Emxgi {^^ Tidasne, 

 Go'iwptes rendusy' 1851, Berkeley and Broome, '^ Brit Association^'' 1851.) 

 — A. H. 



