1546 Journal of Applied Microscopy 



GENERAL PHYSIOLOGY. 



Raymond Pearl. 



Books and papers for review should be sent to Raymond Pearl, Zoological 

 Laboratory, University of Michigan, Ann Arbor, Mich. 



Dewitz, J. Verhinderung der Verpuppung bei In a brief but interesting paper, Dewitz 

 Insektenlarven. Arch. f. Entwickelung- . . r i ^ r 



smech. 11: 690-699, 1901. gives an account of the results of 



experiments on the]_efl[ect of a limited 

 amount of air on the time of pupation of the larvae of flies and other insects. 

 The method of experimentation was to place active larvae in small medicine vials 

 which were filled to different heights with sand. These vials were corked and 

 sealed with wax, and the number of cubic centimeters of contained air recorded. 

 After some days they were opened and the results noted. In case of the larvae 

 of Luciliaccesar, which normally pupates in two days, it was found that after a 

 stay of five days in the corked vials only three larvae out of ninety-five had 

 pupated ; eighteen were dead, and the remaining seventy-four were alive but had 

 not pupated. Left with free access to air these all transformed in two days. 

 Musca larvae were not influenced in their time of pupation by the amount of air, 

 those in the closed tubes transforming as soon as the controls. The author 

 correlates this difference in behavior with the fact that Lticilia larvae do not 

 pupate under natural conditions later in the year than the end of October, while 

 Musca larvae pupate up to the end of November, and indoors throughout the 

 winter. The caterpillars of Pieris brassicce were prevented from pupating by 

 limiting the supply of air. The transformation of the larvae of the ichneumonid 

 Microgaster glomeratus was prevented by placing them in a very moist atmos- 

 phere. R. P. 



Bickel, A. Beitrage zur Gehirnphysiologie der In continuation of his earlier work on 

 Schildkrote. Arch. f. Anat. u. Physiol. Phys- ,, 1 • 1 r ., • 1 1 r 



iol. Abth., 1901, Pp. 52-80. the physiology of the spinal cord of 



the turtle, the author presents this con- 

 tribution on the functions of the brain of the same animal. The results were 

 gained from operation experiments, in which different parts of the brain were 

 isolated or extirpated, and from stimulating the surface of the brain by electrical 

 or chemical means. The wounds from the operations were covered with gela- 

 tine mixed with tannin, the latter preventing the gelatine from dissolving in the 

 water. Most of the work was done on Emys curopcEa, although in a few experi- 

 ments the terrestrial form, Testudo graeca, was used. The operations consisted 

 of complete extirpation by transection of each of the five principal divisions of 

 the brain (forebrain, 'tweenbrain, midbrain, cerebellum, and medulla), and of 

 transverse cuts extending to the middle line at the posterior boundaries of each 

 of these divisions. 



Loss of the forebrain causes a decrease in the frequency with which spon- 

 taneous movements are executed, although there is no difference in the char- 

 acter of the movements themselves under these circumstances. An animal in 

 which the 'tweenbrain has been extirpated, shows a tendency to hold the legs in 



