232 THE PHENOMENON OF 



c. The new cell throws off the membrane of the 

 mother-cell by splitting of the latter into uncoiling spiral 

 filaments : as in the spore of Equisetum (p. 180). 



d. The new cell becomes free by the gradual solution 

 and resorption of the membrane of the mother-cell : as in 

 the pollen-cell of the Phanerogamia, the tetraspores of 

 the Floridese, and the spores, produced in fours, of the 

 Mosses, Liverworts, and Ferns, so far as they really 

 originate in special mother-cells. In the germs Arcltidium, 

 which produces the largest but fewest spores of any of 

 the Mosses, it appears from Schimper's description that 

 the spores are formed singly in the primary mother-cells, 

 and become free through resorption of the latter.* 



B. RECONSTRUCTION WITH DIVISION OF THE CELL INTO 

 TWO DAUGHTER-CELLS. Here we find repeated exactly the 

 same variations as we have seen in the reconstruction with- 

 out division ; on the one side, retention of the previous 

 character (at least in essentials), and ordinarily combined 

 therewith intimate connection of the newly-formed cells 

 with the remains of the mother-cell ; on the other side, 

 decided alteration of character, mostly connected with 

 emancipation from the membranes of the mother-cell. 

 The first case is again characteristic of the divisions con- 

 nected with the development of the vegetative tissues, 

 the latter of the transition to the formation of reproduc- 

 tive cells. Leaving out of view the division which occurs, 

 the analogy with the phenomena of reconstruction of the 

 cell without division is perfect. Thus, for example, the 

 membranes of the daughter-cells originating by division, if 

 these retain the character of the mother-cells, bear exactly 

 the same relation to the membrane of the mother- cell, to 

 which they immediately adhere in their origin, as the 

 thickening layers of the mother-cell where no division 

 occurs, so that if it be correct in the one case to speak 



* 'Recherches sur les Mousses,' p. 77, t. 7, figs. 1 6. According to 

 Schimper, the capsule of Arclddium contains 18 20 spores |th millim. in 

 diameter. 



