



l82 



THE BEGINNINGS OF LIFE. 



a minute or two suffices for the complete evacuation 

 of the club-head or spore-chamber. The spores when 

 they find their way into the water are generally egg- 

 shaped, and swim with the small end foremost. . . . 

 They are extremely small^ their breadth not exceeding 



the 



// 



18 9 6 



of an inch ^.' 



But such a mode of formation of reproductive spores 



method 



rr 



^ The formation of spores in Leptomittis lactens is said by Braun 

 (•Rejuvenescence in Nature/ translation by Henfrey, Ray Society, 1853, 

 p. 270), to take place after precisely the same fashion. The two plants 

 are, in fact, closely allied. In both, according to Braun, the dichotomous 

 filaments are not articulated, they are merely divided into sections by 

 regular strictures, though these sections have been taken for closed cells. 

 He says : — * It is only in the fruit that isolated, mostly terminal sections 

 are actually shut off, swell up to some extent, and become spore cases.' 

 And yet the gonidia of Le/j^om;Vws differ from those oi Achlyahyhtm 

 motionless. In one of the white rusts (Cystopns candldus), moreover, the 

 gonidia, produced in the same fashion, are motionless when discharged, 

 but in a very short time become quite active. (Cooke's 'Microscopic 

 Fungi,' 2nd Edit., 1870, pp. 127, 132, and 142.) The presence or absence 

 of motility in the gonidia probably depends upon minute differences 

 in molecular constitution. We are quite unable to give any precise 

 reason, however, why such a difference should exist between the repro- 

 ductive spores of nearly allied species as is found in these and other 

 cases. In connection with this subject it may be mentioned that I have 

 frequently seen the chlorophyll vesicles within portions of the filament 

 of a Vaiicheria which were about to die, exhibiting slow oscillating 

 movements ; though in the healthy plant they are always quite motion- 

 less. And similarly, in the examination of specimens of human blood 

 with the microscope, I have very frequently seen certain of the red 

 corpuscles in a ' crenated ' state oscillating most distinctly, whilst other 

 normally shaped red corpuscles, which may have been by their side, 

 similarly isolated, and apparently equally free to move, were nevertheless 

 quite motionless. 



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