2 RAMBLES OF A NATURALIST. 



the high roads. My table was daily covered with 

 vessels containing the water which I had brought 

 home with me from these excursions ; and while the 

 aquatic plants that had been left undisturbed were 

 exhibiting an active state of vegetation, the delicate 

 filaments of their roots formed a place of retreat for 

 thousands of those minute beings whose existence 

 and marvellous organisation are only revealed to us 

 by the microscope. There was the Rotifer, whose 

 body, composed of rings fitting into one another like 

 the tubes of a telescope, is provided on its anterior 

 extremity with two wheel-like organs a singular 

 creature, which, although it can only truly live in 

 water, inhabits the moss of our house-tops, dying 

 each time the sun dries up its place of retreat, to 

 revive as often as a shower of rain supplies it with 

 the liquid necessary to its existence, and thus em- 

 ploying several years to exhaust the eighteen days 

 of life which nature has accorded to it.* There was 

 the Hydatina senta, an animalcule allied to the ro- 

 tifer, whose aquatic existence is often cut short by 

 drought, but whose ova, mingled with the dust of 

 our roads, and borne aloft by the winds, are carried 

 far from the place of their origin to some drop of 

 water, where they undergo further development and 

 secure the propagation of their species. The hy- 

 datina is an exquisite little creature of such pure 

 crystalline transparency that the microscope f that 



* [A sketch of the natural history of the Rotifers and their allies is 

 given in the Appendix, Note II.] 



f [We have transferred to the Appendix, Note III., a short history 

 of the microscope, which the author had given as a foot note.] 



