Virus Growth and Variation

injuries of the nervous system. Therefore, this is mainly an analysis of the later after-effects of penetrating brain wounds. The book consists of about 56 pages of well-written succinct text and an extensive appendix with 20 detailed tables of results. There is a useful and thorough list of references and a well defined review of the problem of the cerebral contribution to somatic sensation. The investigators have used as a control group, other veterans without penetrating brain wounds. Three major tests of somatic sensation were applied: punctate pressure sensitivity, two-point discrimination, and point localization, as well as a test of the ability to perceive the direction of small passive movements of the distal phalanx of the middle finger. It has been assumed generally that the representation of sensation of the left hand in the right hemisphere is the mirror image of that of the right hand in the left hemisphere. The results of this investigation produced unexpected data which cast doubt on the validity of this assumption, and suggested instead, that the mode of organization of sensation in the brain is not the same for the right and left hands. Cases with impaired sensation of the right hand showed the classical localization of lesions in the left cerebral hemisphere. Cases with impairment of discriminatory perception in the left hand had cerebral lesions which were widely dispersed. The sensory abilities of the left hand appear, from this study, to be more diffusely represented in the contralateral hemisphere than that of the right hand. Previous studies of cerebral sensory functions have indicated that the left and right parietal lobes are not functionally equivalent, but these differences were mainly in the sphere of complex perceptual disturbances such as the dysphasias, agnosias, apraxias, and anomalies of spatial orientation. The differences described by these workers did not appear to be related to these more complex disorders of sensory function, nor to the presence of a seizure disorder. This monograph is a model of well presented and analyzed neuropsycho-logical data. The results are intriguing and thought provoking since they lead to important questions concerning the differential organization of the two cerebral hemispheres. The publication of symposia on virology has supplanted publication of integrated texts and monographs to a large extent in recent years. This trend has been fostered by the increasing pace of research and the brevity of the period before a book becomes out of …