INFUSORIAL ANIMALCULES. 



37 



Fig. 45. 



XANTHIDIA. The Xanthidia belong to the Desmidiacae, one of the simplest 

 species of the Protophy tes ; it is enclosed pis. 42. Fig. 43. 



in a transparent, single-valved shell, of a 

 globular shape, which resists the action of 

 fire, and is studded with spines or thorns : 

 a green mass is seen in the interior of the 

 body which was once supposed to consist 

 of eggs. The Xantbidia exist both in a 

 living and fossil state, and are found abun 

 dantly in flint, as will be shown hereafter. 

 They exist singly, in pairs, and in groups 

 of four, and increase by self-division. 

 Two figures of living Xanthidia are dis 

 played in figures 44 and 45. Figure 44 is 

 a drawing of a forked Xanthidia, found by 

 Dr. Bailey in a pond near West Point : its 

 shell is green and of oval form, and its 

 natural length is one-two hundred and 

 eighty-eighth of an inch. 



Figure 45 is a different species, and rep 

 resents a spinous Xanthidium, obtained by Dr. Mantell from a 

 Fig. 44. pond in Clapham: it is of the same size as the 

 preceding specimen, and is likewise of a beautiful 

 deep-green hue. 



POLYGASTRIC ANIMALCULES. 



THE PROTEUS. -In figures 46, 47, and 48, a 

 most remarkable animalcule is exhibited, which varies in size from 

 one-one hundred and fortieth to one-seventieth of an inch in length. 

 It appears under the microscope as a pale-yellow mass of jelly- 

 like matter, and is endued with the power of changing its shape to a very extraor 

 dinary degree, as is obvious from the inspection of the figures. From this cir 

 cumstance it is termed the Proteus, the name of the wondrous sea-god, who 

 could assume, at will, every 



form, turning himself into Fig. 46. Fig. 47. 



animals, trees, fire, and 

 water, according to the 

 fables of the classic poets. 



The Proteus can hardly be 

 said to possess any original 

 shape ; for it is capable 



of relaxing itself in one Mbm m&m^ rV ^ ?a 



place, and contracting in 

 others ; and of pushing out 

 from every part of its body 

 long arms and feelers (a a 

 a, &c.), which are its organs 

 of motion, to the number 

 of ten or twelve at one 

 time. These members the 



