342 Mr. A. Henfrey on the Progress of Physiological Botany : 



then be deduced from it. That there is an advancing movement 

 follows from the heliacal shape. That it exhibits various de- 

 viations from the straight line is quite as natural a result of the 

 inequilateral construction, since both the thickness of the fila- 

 ment and the diameter of the convolutions, as well as their di- 

 stance from each other in the same spiral filament, alter succes- 

 sively from one end to the other. 



They differ in chemical composition from the spiral fibres of 

 the spiral tissues of plants, as they give with iodine the charac- 

 teristic reaction of mucilage (a compound which contains nitro- 

 gen) ; the membrane of the cellule remains uncoloured. 



After a comparison of these organs with the antheridia of the 

 other Cryptogamia, from which the author arrives at the con- 

 clusion that they are to be regarded as identical in their nature, 

 he briefly discusses their import and probable function in the 

 following terms : — 



" The antheridia have been compared with the anthers, a 

 misconception which is only applicable by an ignorance or mis- 

 apprehension of the morphology of the elementary organ. I 

 believe no refutation of this view is now necessary. The anthe- 

 ridia have not been compared with other organs of plants : they 

 do not exhibit even a distant analogy to any of them. The only 

 remaining analogy for the antheridia is with the male organs of 

 reproduction of animals. In favour of this speaks the similar 

 course of development of the spermatic filaments in plants and 

 animals, since even in many of the Mammalia, the spermatozoa 

 originate wound spirally in cellules ; further, the resemblance of 

 the motion of the filaments in plants and animals, and, finally, 

 the circumstance that in the Cryptogamia these spermatic fila- 

 ments are the normal elementary parts of an organ, which, from 

 its situation, must evidently have a relation to the reproduction. 

 These reasons certainly appear to me to have great weight ; and 

 if they do not absolutely warrant the assumption that the anthe- 

 ridia are the male organs of the Cryptogamia, they may yet ex- 

 cite further investigation on this ground. 



"The most important objections are : 1. that no organ ana- 

 logous to the antheridia has been found in the Phanerogamia, 

 and that they are themselves wanting in certain Cryptogamia 

 with true spores ; 2. that, as the preceding observations show, 

 the antheridia of the Ferns occur upon the pro-embryo ; so that 

 it is almost impossible to conceive what relation they can here 

 have to the spore-cells, which are formed not merely at a much 

 later period, but first make their appearance long after the pro- 

 embryo has altogether disappeared ." 



The figures illustrating this memoir are taken from Aspidium 



