136 PLANT LIFE. 



Chantransia of Fries, the non-sexual generation of Batra- 

 chospermum : this can propagate itself by simple budding 

 from generation to generation, producing, as a rule, as its 

 organs of propagation, only non-sexual tetraspores. Chan- 

 transia grows especially in dark situations under water, 

 and, when transferred to the light, undergoes a metamor- 

 phosis. There springs up from the Chantransia protoneme 

 a branch which is in every respect a Batrachospermura, and 

 which bears sexual organs only, and no tetraspores. On 

 one species only of Chantransia, C. corymbifera (Thur.), 

 are sexual organs known. Although this phenomenon is 

 sometimes spoken of as an example of 'alternation of 

 generations,' it is not identical with the process known 

 under that name in the higher Cryptogams, being rather a 

 difference in the mode of development, dependent on a 

 change in the vital conditions." 



The following abstract illustrates Mr. A. W. Bennett's 

 new arrangement of the Algae, including the chlorophyllous 

 Protophyta, in accordance with their affinities.' 



" Too little importance has," he considers, " at present 

 been attached to degeneration or retrogression, which may be 

 exhibited in the partial or complete suppression of either 

 the reproductive or the vegetative parts." 



He traces all the various forms of vegetable life to three 

 lines of descent, represented by three distinct kinds of cell- 

 contents — colourless, blue-green, and pure green. The first 

 appears to originate in the Bacteria or Schizomycetes, from 

 which are derived the whole group of Fungi. The second 

 primordial type consists of unicellular organisms, in which 

 the cell-contents are composed of a pale, watery, blue-green 



' Journal of the Linnaan Society, London : " Botany," xxiv. (1887), 

 pp. 49—61. 



