202 NATURAL HISTORY. 



these are again subdivided, until they become thin as 

 threads. These branches consist of innumerable osseous 

 segments or plates. The color is generally red, some- 

 times, however, it is found gray, green, yellow, or black. 

 Seen under water, it resembles an expanded flower, but 

 when but slightly raised in the water, the serrated rays 

 hang down like flaps ; but if drawn forth entirely it 

 fastens from above on the hand, which not a little alarms 

 the intruder, who, believing only to have grasped a mass 

 of inert matter, finds it a living creature, and disposed to 

 resent. It dies immediately. Contracting all its radii 

 into a globose form, it folds itself up like a plant that 

 closes its petals at night. It can not be kept, even with 

 the greatest care, but a very short time, as it is exceed- 

 ingly brittle, and the joints very slightly connected. 



FOURTH ORDER. 

 INFUSORIA. 



The infusory animals or animalculse, found in all waters 

 more or less corrupted, are so minute that few of them can 

 be seen with the naked eye. But, notwithstanding their 

 extreme smallness, the microscope has enabled the natur- 

 alist to discover the form and trace the organization of 

 these creatures, which form the last series of beings in 

 the animal scale. Professor Ehrenberg has been suc- 

 cessful in discovering their existence, as well as organi- 

 zation, in the infusions of different plants, such as 

 carmine, blue, etc., which, used for dying, contained ani- 

 malculae. These Infusioria, receiving the colored fluid, 



