16 POND LIFE 



cell will swim independently, as if it were quite an ordinary 

 event to be separated from its relations. 



To the amateur mycologist one might say, " Find a volvox 

 and be happy " ; for it may be said that there are very few things 

 more beautiful, more original, and more extraordinary than 

 this little plant. 



Another of great interest, a member of the family, is Pan- 

 dorina morum. It is very common in many districts, and is 



4. 



VOLVOCINEAB 

 1. Volvox globator, showing daughters inside parent. 2. Pandorina morum. 



CYANOPHYCEAE 



- 3. Oscillatoria tenuis. 4. Nostoc. 



often mistaken for Volvox globator by the amateur. It is com- 

 posed of a few large green cells, noticeable for a red spot 

 nearest to the broad side. Each cell has a pair of long cilia, 

 and the entire colony is surrounded by a gelatinous envelope, 

 through which the cilia protrude. Their method of reproduc- 

 tion is rather different to that of volvox. The cells break out 

 of their envelope, and swim freely until two of them meet ; 

 these then join together and spores are formed. 



