392 Recent Literature. [April, i 
tionist, believing that there is a blood relationship between the 
branches, twigs, and trunk and roots of his tree-like system, he 
acknowledges the fact that his graphic presentation of his system- 
atic views really approximately represents what has actually 
taken place in nature. The branches of his genealogical tree are 
approximative to what practically are lines of descent or ascent 
Certain twigs may be bent backward or downward, and they rep- 
resent degradational paths, along which retrograde forms have 
traveled. eg 
The historian of families or of nations constructs genealogical f 
trees, and is it illogical that the naturalist should? Errors creep 
into historical genealogical trees. No two naturalists may construct 
the same form of genealogical tree for the same order or class; 59 | 
no two observers agree as regards the classification of amy group. — 
Because our attempts at expressing our conceptions as to the els 
gin and descent of certain groups are imperfect and provisional, it 
does not follow that the attempt should be ridiculed by those r 
naturalists who are excellent as systematists and anatomists, but 
who do not work with their thinking caps on. : 
RECENT LITERATURE. 
Sexvey’s HISTORY or THE SKULL.—This pamphlet isa 
the various relations between the skull and the other structu | 
a vertebrate, with a view “ to stimulate some other fellow-w0 ie a 
to seek for the meaning” of the unknown points in the pr ene 
Professor Seeley shows: (1) That comparative ana ae | 
an increasing simplification and approximation to the hat en- : 
plan as we ascend the scale from fishes to mammals; yett t have 
bryology shows that the skull originates in structures tM a 
little in common with the vertebre, (2) That a skull 1s of the 2 
to define, for the branchial arches appear to be survivals 0! T A 
somatic clefts of Amphioxus, and the visceral clefts of pre fa) 
mammal are homologous with the branchial arches of a BSA 5. 
That a skull, as usually understood, consists of, first, a Drar i 
second, of jaws, and third, of structures connected a sep- 
_ tion, which parts may, as in the sharks, have been origt®® d ar | 
rate. (4) That the bones surrounding the nasal, opte ott 
aitory Cap les kat ly constant, especially the latter, about - 
it would appear that a brain-case “ is a union of ossification i his 
sense-capsules that have come to surround the brain, 7 
will not explain either the number or arrangement of the pata 
(5) That the cartilaginous cranium originates from © suggest 
chordals and trabeculz, which primitive elements do aii ddt 
that tri-partite segmentation of the skull which 1s finally © 
‘The History of the Skull, by Professor H. G. Seeley, F.R.S» F.LS. i 
on. . 2 
view of 
eth 
Ait 
. 
fore the Science Society, of King’s College, Lond 
