322 JUNGERMANNIACEJS. PAST n. 



stems, and the elaters spring out of their cells, and 

 disperse the spores. 



The plants of this order are also reproduced by 

 gonidia, but in such numerous genera and species the 

 arrangement of the reproductive bodies and their minute 

 details are exceedingly varied. They are chiefly dis- 

 tinguished by the insertion of the fruit, and the form of 

 the different organs which surround it. They are pretty 

 little plants, occasionally of a bright green, but oftener 

 inclined to red, purple, and chocolate colour ; a few are 

 fragrant, but they are of no known utility. They are 

 found in shady woods and moist situations, throughout 

 all regions of the globe, but are most abundant in damp, 

 tropical forests. 



In all the families of the leafy Cryptogamia as well as 

 in the Hepaticae, antheridia exist ; they differ much in 

 form, and structure, but they collectively agree in de- 

 veloping in the interior of delicately walled cells, an 

 amorphous substance, coloured yellow by iodine, in place 

 of which, at the epoch of maturation, spermatozoids 

 appear, thick at one end and running to a very fine 

 point at the other, and displaying several spiral convo- 

 lutions. When rolled up like a watch-spring the mo- 

 tion is more or less rotary, but if it be coiled in the 

 form of a corkscrew, the movement is at the same 

 time advancing. The thin end of the filament always 

 goes first both within the cell and after it comes out. 3 

 The whole structure of the Hepaticse is full of objects 

 of interest to the microscopic observer. 



3 ' Anatomy and Physiology of the Vegetable Cell/ by M. Hugo von 

 Mohl. 



