BRISTLE-TAILS AND SPRING-TAILS. 97 
referred Campodea to the old genus Podura, says with much truth, 
“it may be perhaps no unfair inference to draw, that the insect in 
question is in some measure intermediate between both.” This is 
seen especially in the mouth-parts which are withdrawn into the 
head, and become very rudimentary, affording a gradual passage 
into the mouth-parts of the Poduride, which we now describe. 
The next group, the Podurelles of Nicolet, and Collembola of 
Lubbock, are considered by the latter, who has studied them with 
far more care than any one else, as ‘less closely allied” to the Le- 
pismidee “than has hitherto been supposed.” He says “‘ the pres- 
ence of trachez, the structure of the mouth, and the abdominal 
appendage, all indicate a wide distinction between the Lepismide 
and the Poduride. We must, indeed, in my opinion, separate 
them entirely from one another; and I would venture to propose 
for the group comprised in the old genus Podura, the term Collem- 
bola, as indicating the existence of a projection, or mammilla, en- 
- abling the creature to attach or glue itself to the body on which it 
stands.” Then without expressing his views as to the position 
and affinities of the Lepismidz, he remarks “as the upshot of all 
this, then, while the Collembola are clearly more nearly allied to 
the Insecta than to the Crustacea or Arachnida, we cannot, I think, 
regard them as Orthoptera or Neuroptera, or even as true insects. 
That is to say, the Coleoptera, Orthoptera, Neuroptera, Lepidop- 
tera, etc., are in my opinion, more nearly allied to one another 
than they are to the Poduride or Smynthuride. On the other 
hand, we certainly cannot regard the Collembola as a group equiv- 
alent in value to the Insecta. If, then, we attempt to map out 
the Articulata, we must, I think, regard the Crustacea and Insecta 
as continents, the Myriapoda and Collembola as islands — of less 
importance, but still detached. . Or, if we represent the divisions 
of the Articulata like the branching of a tree, we must picture the 
Collembola as a separate branch, though a small one, and much 
more closely connected with the Insecta, than with the Crustacea 
or the Arachnida.” Lamarck regarded them as more nearly al- 
lied to the Crustacea than Insecta. © Gervais, also, in the “ Histoire 
Naturelles des Insectes : Apteres,” indicates a considerable diver- 
sity existing between the Lepismide and Poduride, though they 
are placed next to each other... Somewhat similar views have been 
expressed by so high an authority as Professor Dana, who, in the 
‘‘ American Journal of Science ” (vol. 37, Jan., 1864), proposed a 
AMER. NATURALIST, VOL. V. 
