THE BEGINNINGS OF LIFE. 173 



with a little beak, a kind of anterior process, always 

 distinguishable from the body of the seed by its paler 

 colour. . . . Escaped from their prison they con- 

 tinue their motion for one or two hours, and retiring 

 always towards the darker edge of the vessel, some- 

 times they prolong their wandering course, sometimes 

 they remain in the same place, causing their beak to 

 vibrate in rapid circles. Finally they collect in dense 

 masses, containing innumerable grains, and attach 

 themselves to some extraneous body at the bottom or 

 on the surface of the water, where they hasten to 

 develope filaments like those of the mother plant.' 



The mode of formation of the single ciliated spore 1 

 of Vauckeria is perhaps still more interesting, because 

 the parent organism, which is a fine tufted filamentous 

 Alga, presents not the slightest trace of a cellular 

 structure, and because of the rapidity with which the 

 spore is produced. The ramified tubular structure of 

 the Alga is lined with minute but bright green chloro- 

 phyll vesicles or granules. All the phenomena which 

 attend the formation of the spore were frequently 

 observed, and have been carefully described by Dr. 

 A. H. Hassall, from whose work 2 we abstract the 

 following details. When spores are about to form, 

 the extremities of some of the filaments swell up in 

 the form of a club, and the green matter becomes so 

 much condensed at this part as to make it assume a 



1 About -^-3" in diameter. 



2 History of the British Fresh Water Algae,' 1845, p. 16. 



