based on the principle of Cephalization. 337 
osculant groups; so may the amplificative feature of great length 
of limb and neck, the Herons among the Altrices, thus repre- 
senting the Grallatores among the Precoces. 
The osculations or close approximations of classes, orders, 
tribes, etc., are thus often connected with like expressions of the 
methods of cephalization. 
4. Forms resulting from high and low cephalization sometimes 
similar.—High and low cephalization often lead to similar forms, 
the former through cephalic concentration, the latter through 
cephalic and general feebleness; just as a thing may be small, 
when the material is condensed or concentrated, and equally 
small when dilute and there is little of it. Thus the Crab has a 
very small memberless abdomen, fro contracting of the 
sphere of growth through concentrative cephalization; on the 
other hand, the Schizopod has a membe abdomen, through 
ness in the life-system. The abbreviated memberless abdomen 
of the Caprellid and the obsolescent spine-like abdomen of the 
Limulus are other examples among Crustaceans of this eiliptic 
decephalization. See also page 6 of this volume for a compari- 
son of a Limulus and an Insect. The Butterflies have very 
large wings through the amplificative method; but some inferior 
nocturnal species have the wings narrow through inferiority of 
grade, on the above principle, and not properly through concen- 
tration and elevation. 
There is, in general, no danger of confounding the two cases, 
because the accompaniments in the structure of the superior 
Species, as well as those of the inferior, commonly indicate their 
true relations, at once, to the mind that is well versed in the 
department of zoology to which the species belong. But there 
are many cases in which it is not safe to make a hasty decision. 
Tnsects, the Hymenopters have little variety of form of body, 
In these, cephalization is of low grade, and as a consequence of 
is relaxing of the system, or its inferior concentration, the 
forms run off into varied extravagances. 
