xiv JouRNAL OF COMPARATIVE NEUROLOGY. 
in the Simiide and larger Cercopithecidz) is longer and deeper; and 
the diagonal sulcus, rarely or never seen in a well-developed form in 
the Apes, is now almost constantly present as a deep, extensive sulcus, 
lying between the anterior ascending limb of the Sylvian and the in- 
ferior precentral sulcus. 
The parietal area is notably much more variable and much richer 
in secondary sulci than it is in the Apes. 
In the temporo-occipital region the ‘‘Affenspalte” of the Apes has 
disappeared, and the depth and extent of the dorsal end of the parallel, 
the transverse occipital and lateral occipital sulci are correspondingly 
increased. ‘The inferior occipital, inferior temporal, occipito-temporal, 
and collateral sulci are usually all present in a well-developed form. In 
the Apes the deepening and lengthening of any one of these sulci in- 
volved a dwindling of its neighbour—a highly developed occipito-tem- 
poral sulcus often led to the abortion of the inferior temporal, the dis- 
appearance of the anterior end of the collateral, or the curtailment of 
the inferior occipital or vice versa ; but in the human brain there is room 
for all these unstable and mutually compensatory sulci to exist in a well- 
developed form side by side. 
The expansion of the neopallium has far-reaching effects upon 
other regions of the nervous system: the fiber systems connected with 
it become more bulky, the cerebellum becomes larger, its middle ped- 
uncle—the pons—becomes so broad that it completely covers the 
trapezoid bodies and extends down to the inferior olives. In innumer- 
able ways the whole nervous system is profoundty influenced and 
modified in structure as the result, directly or indirectly, of the attain- 
ment of the neopallium to the height of its perfection. 
Obsessions and Psychasthenia.' 
In this new work, which, like its predecessors on hysteria and on 
fixed ideas, deals with large groups of so-called neuroses, P. JANET 
brings a number of features under a definite heading, the obsessions, 
impulsions, manias, folly of doubt, tics, agitations, phobias, mysopho- 
bias, anxieties, the feelings of insufficiency, neurasthenia and the modi- 
fications of the feelings of reality. The very list of these titles gives 
us a feeling of the confusion that exists in the use of the terms, and we 
must be grateful to see a more definite entity, after the pattern of 
epilepsy and hysteria, bring a new order into these conditions 
so loosely thrown together with neurasthenia. This _ spe- 
cialized group is termed psychasthenia. The analysis of the 325 
patients has led JANET to the recognition that all these types depend on 
a lowering of the ‘‘psychological tension.” Whereas hysteria shows a 
complete suppression of ‘certain facts and an exaggeration of others, 
? Dr. PIERRE JANET, Les Obsessions et la Psychasthénie. Vol. I. Félix 
Alean, Paris, 1903. 
