reference to the peculiar conditions of both mother and off- 

 spring, afford, as it seems to me, irrefragable evidence of 

 Creative foresight. 



The LISSENCEPHALA, or smooth-brained placental Mam- 

 malia, form a group which I consider as equivalent to 

 the LYENCEPHALA or Implacentals ; and which includes the 

 following orders, Rodentfa, Insectivora, Cheiroptera and 

 Bruta. 



The RODENTIA are characterized by two large and long- 

 curved incisors in each jaw, separated by a wide interval 

 from the molars ; the teeth being so constructed, and the 

 jaw so articulated, as to effect the reduction of the food 

 to small particles by acts of rapid and. continued gnawing, 

 whence the name of the order. The orbits are not separated 

 from the temporal fossa?. The male glands pass periodically 

 from the abdomen into a temporary scrotum, and are asso- 

 ciated with prostatic and vesicular glands. The placenta is 

 commonly discoid, but is sometimes a circular mass (Cavy), 

 or flattened and divided into three or more lobes (Lepus). 

 The Beaver and Capybara are the giants of the order, which 

 chiefly consists of small, numerous, prolific and diversified 

 unguiculate genera, subsisting wholly or in part on vegetable 

 food. Some Rodents, e.g. the Lemmings, perform remark- 

 able migrations, the impulse to which, unchecked by dangers 

 or any surmountable obstacles, seems to be mechanical. 

 Many Rodents build very artificial nests, and a few manifest 

 their constructive instinct in association. In all these inferior 

 psychical manifestations we are reminded of Birds. Many 

 Rodents hibernate like Reptiles. They are distributed over 

 all continents. About two-thirds of the known species of 

 Mammalia belong to the Rodent order. 



The transition from the Marsupials to the Rodents is 

 made by the Wombats ; and a transition from the Marsupials 

 is made, by an equally easy step, through the smaller Opos- 

 sums to the INSECTIVORA. This term is given to the order of 

 small smooth-brained Mammals, the molar teeth of which are 



