104 ROMANCE OF LOW LIFE AMONGST PLANTS, 



\vhich were now arranged in curved rows, closely 

 rolled together into balls. Upon the upper surface 

 of the section appeared little gelatinous balls, or 

 warts, which contained gonidia in rows, and gradu- 

 ally developed typical Nostoc forms ; whilst on the 

 edges of the sections appeared little colourless wart- 

 like masses of jelly, in which, after some time, appeared 

 gonidia, some of which developed into the typical 

 Nostoc forms, others into true collemoid plants. He 

 further states that he watched the body of the section 

 gradually change, by the continual growth and in- 

 crease of the rows of gonidia alluded to, and by the 

 disappearance of the collemoid threads, until at last 

 the whole mass of the tissues of the lichen had been 

 converted into a true Nostoc, which was finally identi- 

 fied as Nostoc vcsicarijini (D.C.). Thus it will be 

 observed, if both the above accounts are to be relied 

 upon, Nostoc commune produces Collema pulposiim ; 

 and Collema pulposnm originates Nostoc vesicarium, 

 and not Nostoc commune} 



Boiled Alg^. 



Amongst the most beautiful of the fresh-water 

 algae which are found in our ditches and streams, are 

 the different species of Batrachospcnmim, which are 

 great favourites with all young microscopists (Fig. 20). 

 The number of species is dependent very much upon 

 individual opinion as to the limits of species, some 

 botanists believing in a large number of species, 

 others in but a small number of species, with a great 



' Further observations on this subject, by Dr. Braxton Hicks, will be 

 found in the Quarterly Journal of Microscopical Scietice, 1861, p. go. 



