62 HALF-HOURS IN THE GREEN LANES. 



We have already referred to the Algae the green 

 scum that mantles every standing pool. Space, 

 however, only permits us to point out that in the 

 microscopical study of the humble forms of this 

 group there is a world of interest, engaging the 

 attention of some of our best men of science. For 

 it will only be by familiarising ourselves thoroughly 

 with the nature and organisation of these lowly 

 forms, both animal and vegetable, that we shall 

 ever be able to rise to a thorough understanding of 

 those complex organisations which distinguish the 

 highest organisms. 



The Volvox (Fig. 56) has been, in its time, bandied 

 about from the animal to the vegetable kingdom, 

 until its real nature was known. It is now set 

 down as one of the confervoid algae, and, although 

 only just visible to the naked eye, it may be found 

 in such a tarn as that whose chief contents we have 

 been endeavouring to describe. In the aquarium, it 

 may be observed rolling through the water in pretty 

 much the same manner that a balloon makes its way 

 across the sky on a still day. Only a low optical 

 power is required, to convince the young naturalist 

 that he has in the volvox one of the prettiest objects 

 it is possible to imagine. It is a globe of the 

 most delicate green colour formed of a transparent 

 membrane, which is marked with a net-work of 

 fine lines, ornamented with darker green spote just 

 where the lines cross. What is most singular is 

 the manner in which the volvoces reproduce them- 



