FLOWERLESS PLANTS. 67 



even of these are not such as pertain to proper leaves, 

 the plant taking up nutriment in every part alike. 

 The parts analogous to flowers are contained in 

 smaller vesicles, found chiefly near the extremities of 

 the branches. They are too delicate to be distinguished 

 without the aid of the microscope, but then excite the 

 liveliest astonishment, so lively and so novel are the 

 phenomena by which their energy is manifested. 

 Fresh water contains plants of much the same general 

 character as the weeds of the sea. These are usually 

 green, never purple or rose-colored, like many of those 

 that live in salt water ; and their structure is in many 

 cases much more simple. Every pond, and stream, 

 and fountain pool contains abundance of light green 

 cloudy matter, which when carefully taken out and 

 diffused in a basin of water, is found to consist of thin 

 threads, finer than the finest silk. Examined with the 

 microscope these threads present the appearance of 

 necklaces, consisting of numerous oblong cells or 

 beads joined end to end. A very common species, 

 called by botanists Zygnema, illustrates the process 

 of seed-production in the most striking manner. The 

 cells are filled with dark-colored granules, and as soon 

 as these are ready, the cells of adjacent threads unite 

 by their surfaces ; a passage is opened from one into 

 the other ; the contents are all transfused ; and the 

 cells that are made the receptacle of this commixture 

 become as it were the seed-pods. So marvellous are 

 the disclosures of the microscope I 



