To see the nuclei distinctly the plant may be first of 

 all killed and hardened in absolute alcohol or Flemmings' 

 chrom-osmiun-acetic solution, then washed in water and 

 stained in a dilute solution of hematoxylin or in Meyer's 

 acid carmine for some time, then cleared in the usual way 

 and mounted in balsam. We then find, both in the 

 protoplasm lining the spherical vesicle above ground and 

 in the rhizoids, that the nuclei possess a distinct nuclear 

 membrane and a deeply stained nucleolus. The chromatic 

 substance appears to reside wholly in the nucleolus. 

 In the green portion of the plant the nuclei are in close 

 contact with the chromatophores, and in the majority of 

 cases each chromatophore possesses one nucleus in close 

 contact with it. In some cases a nucleus is found in 

 contact with two chromatophores, rarely with three or four. 



The division of the nucleus has been observed in the 

 rhizoids. The nuclear membrane disappears, the chromatic 

 substance forms a number of chromosomes, which arrange 

 themselves into an equatorial plate, with a nuclear spindle. 

 They then separate into two equal groups, which become 

 transformed into daughter nuclei. The process does not 

 appear to differ in any essential from that observed in the 

 higher plants, except that no longitudinal splitting of the 

 chromosomes could be observed. This may be due to 

 their small size, which prevents all the details of nuclear 

 division from being accurately observed, or it may be that 

 no longitudinal splitting occurs. The chromatophores are 

 large, irregular in shape, and more or less equally spaced 

 in the living layer of protoplasm. In sections, cut with 

 the ribbon section cutting microtome, they were found to 

 occur in layers one, two, and sometimes three deep, 

 according to the stage of development of the plant. 



Reproduction. 



We owe to Rostafinski and Woronin* our knowledge 



of the somewhat complicated life history of this plant. 



It reproduces itself, according to these observers, both 



asexually and sexually, and is also capable of vegeta- 



* Ueber Botrydium granulatum, Botanische Zeitung-, Vol. 35, 1877. 



