RECENT ADVANCES IN SCIENCE 581 



figured. In the second paper it is shown that the chromosomes, 

 including an X and Y, appear in the spermatogonia! complex. 

 The occurrence of Parasynapsis at the early stage of division 

 is not substantiated. 

 Other papers include : 



Brues, " The Classification of Insects on the Character of the Larva and 

 Pupa " (Biol. Bull., vol. xxxvii, July 1919) ; Burnes, "' Experiments in 

 Breeding as a Means of determining Some Relationships among Cyclops " 

 (ibid., July 1919) ; Davey, " Prolongation of life of Tribolium confusum 

 apparently due to Small Doses of X-rays" (Journ. Exp. Zool., vol. xxviii, July 

 I 9 I 9) ; Green, " Studies in the Life-cycle of Simnocephalus vetulus " (Biol. 

 Bull., vol. xxxvii, July 1919) ; Kornhauser, " The Sexual Characteristics of the 

 Membracid, Thelia bimaculata (Fabr.) : I, External Changes induced by Aphe- 

 lopus thelice (Gahan) " (Journ. Morph., vol. xxxii, Sept. 1919) ; and Whiting, 

 " Genetic Studies on the Mediterranean Flour Moth, Ephestia kuhniella Zeller " 

 (Journ. Exp. Zool., vol. xxviii, July 1919). 



Vertebrata. — " The Comparative Myology of the Shoulder 

 Girdle and Pectoral Fin of Fishes " is discussed at some length 

 by Shann {Trans. Roy. Soc. Edin., vol. lii, pt. iii, 1919). A 

 series of twenty species of the class ranging from Selachii to 

 Teleostei were dissected, and a description of the musculature is 

 given in each case. In addition to the actual account, there is 

 also provided a " Key to Comparative Study of Pectoral Muscu- 

 lature " in the six different groups, and also in the Urodela, and 

 again a tabular statement of the nomenclature employed by the 

 various authorities in the Elasmobranchii, both of which are 

 very useful. 



Other papers include : 



" The Homologies of the Maxillary and Vomer Bones of Polypterus " (Amer. 

 Journ. Anat., vol. xxv, July 1919), and " The Innervation of the Intermandi- 

 bularis and Genioglossus Muscles of the Bony Fishes " (Anat. Rec, vol. xvi, 

 July 1 91 9), both by Phelps ; Turner, " The Seasonal Cycle in the Spermary 

 of the Perch" (Journ. Morph., vol. xxxii, Sept. 1919) ; Allen, " Development 

 of the Thyroid Glands of Bufo and their Normal Relation to Metamorphosis " 

 (ibid.); Hoskins, "Growth and Development of Amphibia as affected by 

 Thyroidectomy" (Journ. Exp. Zool., vol. xxix, Aug. 1919) ; Jordan, "The 

 Histology of the Blood and the Red Bone-Marrow of the Leopard Frog, Rana 

 pipiens " (Amer. Journ. Anat., vol. xxv, July 191 9) ; Kampmeier, " A Sum- 

 mary of a Monograph on the Morphology of the Lymphatic System in the 

 Anuran Amphibia, with Especial Reference to its Origin and Development " 

 (Anat. Rec, vol. xvi, Aug. 1919) ; Latta, " The Morphology of the so-called 

 Balancers in Certain Species of Amblystoma " (ibid., Sept. i9!9) ; Larsell, 

 " Studies on the Nervus Terminalis : Turtle " (Journ. Comp. Neur., vol. xxx, 

 Aug. 1919) ; and Tannreuther, " Partial and Complete Duplicity in Chick 

 Embryos " (Anat. Rec, vol. xvi, Aug. 1919). 

 38 



