THE CRYTOPS SAVIGNI. 42$ 



undergo changes somewhat like the JulidcB before attaining the 

 adult stage. The species of the genus Crytops, when full grown, 

 have inconspicuous eyes, seventeen joints to the antennae, and 

 twenty-one pairs of feet. But when they are young they have no 

 mouth, and nothing like it is to be seen when the microscope is 

 used ; there is, however, a rounded aperture at the back of the 

 head, and fringed at its margin. It is remarkable that one of 

 the species of the genus, Crytops Savigni, should have no less than 

 twenty-nine joints to its antennae in its imperfect state, but 

 only seventeen in the adult form, so that there is a retrograde 

 development during the successive moultings and the corres- 

 ponding structural changes. 



One genus, Scutigcra, has a slim body, but very great legs 

 and antennae ; and the growth of Scutigera araneoides is very 

 remarkable, according to Fabre, especially with reference to the 

 front and hind parts of the body. The young are furnished with 

 only seven pairs of feet ; but during development the number of 

 the segments, legs, and ocelli, besides the number of the joints of 

 the antennae and tarsi, increases. The segments which bear the 

 first seven pairs of feet, and which exist at the moment of birth, 

 form the half of the body which contains the organs of the senses 

 and the essential parts of the digestive apparatus; whilst the 

 other half, which lodges the reproductive apparatus, is developed 

 subsequently. Fabre appears to consider that the first part 

 represents the larva, which only manifests the life of the individual, 

 and the posterior portion the perfect insect, in which resides the 

 life of the species. This fancy may be of course applied to the 

 case of the Juliis; but it only testifies to the vivid imagination 

 of an able naturalist. The same author has observed the phases 

 in the development of Lithobius forficatus. It is born with ten 

 segments, seven pairs of feet, seven joints on its antennae, and 

 two ocelli. Two months elapse, and the Myriapod is observed to 

 have seventeen segments, fifteen pairs of feet, six ocelli on each 

 side of the head, and twenty-six joints to its antennae. 



The Myriapoda are very ancient creatures, and doubtless the 

 Julns that was found in a tree stump in a coal seam in Nova 

 Scotia by Dr. Dawson took as long to mature during a series of 

 moults, which imitated metamorphosis, as its modern descendants. 



