ORDER OF MONOTREMATA. 
“ Natura non facit salturn ” was a dictum of Linnaeus, which means 
that there exist between all living beings gradations and transi- 
tions, which render a rigorously exact classification very difficult, 
and sometimes impossible. We said in the preceding volume of 
this work : “ Nature makes transitions, Naturalists make divisions” 
For, in fact, there do not exist in organised beings such accurately 
marked divisions as naturalists have invented for facilitating 
their studies. All is connected and linked together in creation. 
Creatures pass insensibly, without fits or starts, from the simplest 
to the most complex organization ; from the rudest to the most 
advanced. Nature arranges these transitions with infinite art ; 
she softens down, by intermediate tints, the crudity which might 
result from the contrast of very different colours. All the parts 
of the grand work are thus blended together with a sublime 
harmony, which fills the soul of the observer with a well-merited 
admiration. We shall find in the first order of Mammalia a 
striking confirmation of these ideas.* The Monotremata resemble 
at the same time Mammalia, Birds, and Reptiles. In the Monotre- 
mata, as in birds, the urine, the excrements, and the products of 
generation, are evacuated by one common orifice, named the cloaca . 
The name Monotremata, given them by M. Geoffroy Saint-Hilaire, 
very well expresses this principal peculiarity of their organiza- 
tion : it signifies one single hole (fiovog, single, alone ; rpri/ua , 
an orifice). Nevertheless this characteristic alone would not 
suffice to enable us to recognise the animals which we are now 
occupied in considering ; for this is found equally among certain 
of the Edentata. And so De Blainville thought that we ought 
to substitute for the preceding denomination that of Ornitho- 
* It must not be supposed, however, that in the existent condition of the animal 
kingdom, there is a complete intergradation of all forms of life, such as the author 
apparently contends for. This is very far from being the truth. — E d. 
