t,66 SCIENCE PROGRESS 



a fully illustrated description of the relations between the parts 

 indicated in their titles. The procoelomic diverticulum divides 

 into two tubes, which pass forwards in a cartilaginous tube to 

 the ex-occipital bone. They enter canals in the bones, and 

 each divides into two, one passing to the pterotic and the other 

 to the pro-otic bone, and each subdivision enlarges to form a 

 vesicle. 



Other papers include : 



Grave, " Amaroucium pellucidum (Leidy) form constellatum (Verrill). 

 I, The Activities and Reactions of the Tadpole Larva " {Jour. Exp. Zool., 

 vol. XXX, no. 2, Feb. 1920) ; Hosford, " A Note on the Hyobranchial Skeleton 

 of Squalus acanihias " {Anat. Rec, vol. xviii, no. 3, April 1920) ; Moodie, 

 " The Nature of the Primitive Haversian System " {ibid., vol. xix, no. i, 

 June 1920) ; Norris and Hughes, " The Spiracular Sense Organ in Elasmo- 

 branchs, Ganoids, and Dipnoans " {ibid., vol. xviii, no. 2, March 1920) ; and 

 Olmsted, " The Nerve as a Formative Influence in the Development of 

 Taste-buds " [Jour. Comp. Neur., vol. xxxi, no. 5, June 1920). 



Reed has investigated in detail in a number of forms " The 

 Morphology of the Sound-transmitting Apparatus in Caudate 

 Amphibia, and its Phylogenetic Significance " {Jour. Morph., 

 vol. xxxiii, no. 2, March 1920). There are always two elements 

 present, columella and operculum, and in the generalised 

 condition they are independent. In a large number of families, 

 however, they fuse to form a single plate. " The nature and 

 relations of the sound-transmitting apparatus indicate that 

 these structures came into their present state in a terrestrial 

 environment. Results gained from this study, combined with 

 others, tend to confirm the view that the present-day aquatic 

 species are secondarily so ; that some species give evidence of 

 just beginning a return to an aquatic abode ; that others are 

 still strictly terrestrial, and hkely to remain so." 



Other papers include : 



Allen, " The Results of Earliest Removal of the Thymus Glands in Rana 

 pipiens Tadpoles " and " The Parathyroid Glands of Thyroidless Bufo 

 Larvae " (both Jour. Exp. Zool., vol. xxx, no. 2, Feb. 1920) ; Burr, " The 

 Transplantation of the Cerebral Hemispheres of Amblystoma " {ibid., no. i, 

 Jan. 1920) ; Cummins, " The Role of Voice and Coloration in Spring 

 Migration and Sex Recognition in Frogs " {ibid., no. 3, April 1920) ; Jewell, 

 " The Effects of Hydrogen Ion Concentration and Oxygen Content of Water 

 upon Regeneration and Metabolism of Tadpoles " {ibid., no. 4, May 1920) ; 

 Larsell, " The Cerebellum of Amblystoma " {Jour. Comp. Neur., vol. xxxi, 

 no. 4, April 1920) ; Latimer, " The Weights of the Viscera of the Common 

 Frog " {Anat. Rec, vol. xviii, no. i, Feb. 1920) ; Sagouchi, " Studies on the 

 Glandular Cells of the Frog's Pancreas " {Amer. Jour. Anat., vol. xxvi, no. 3, 

 Jan. 1920) ; Smith, " The Hyobranchial Apparatus of Spelerpes bislineatus " 

 {Jour. Morph., vol. xxxiii, no. 2, March 1920); Vincent and Cameron. "A 

 Note on an Inhibitory Respkatory Reflex in the Frog and some other 

 Animals " {Jo^tr. Comp. Neur., vol. xxxi, no. 4, April 1920) ; and Wilson and 

 Markham, " Asymmetrical Regulation in Anuran Embryos with Spi n 



