A GENERAL SURVEY 7 



get on very well wherever there happens to be 

 a little moisture ; even under very dry con- 

 ditions they will pass into a state of quiescence, 

 from which they are able to awake into full 

 activity with the arrival of damper conditions. 

 A huge number of algse are of the simplest 

 possible formation, though some, particularly 

 the seaweeds, show signs of a higher formation. 

 Many of these plants attain a great size (actually 

 some of the ocean weeds are almost the biggest 

 plants in the world) and show a division into 

 organs which bear a superficial resemblance, at 

 any rate, to the leaf, root, and stem of the 

 higher plants. 



Amid such a range of forms, hving under 

 all kinds of conditions, it is no surprise to find 

 that the methods of reproduction show a good 

 deal of variety. In some instances it is possible 

 to recognise a definite sex method of repro- 

 duction ; in other cases the new individual 

 arises after the emergence of the cell contents 

 from its surrounding wall, whilst a very common 

 mode consists in the mere splitting up of the 

 cells. It is interesting to notice that many 

 species of algae have more than one method of 

 reproduction available, the particular process 



