188 SUMMAEY OF CURRENT RESEARCHES RELATING TO 



(ear-dust) consisting of separate crystals of carbonate of lime. In a 

 previous paper * the author dealt with the sacculus and its otoliths in a 

 variety of types. 



Blood Vessels of Rabbit's Mammary Gland.t— H. M. Wahl finds 

 that the blood supply of the mammary gland during development and 

 rest appears in the main to be secondary to the blood supply of the 

 skin and the subcutaneous muscles. During functional activity, 

 however, it becomes more independent, the blood supply of the alveoli 

 being connected with the vessels of the ducts, and to a large extent, at 

 least, independent of that of the stroma. The author points out that 

 the irregularity in the retrograde metamorphosis of the gland and the 

 changes in the blood supply are suggestive in relation to cancer- 

 formation. 



INVERTEBRATA. 



MoUusca. 

 y. Gastropoda. 



Structure of Burmese Slug.J — Ekendranath Ghosh describes in 

 Atopos {FarajJO(la/i/j/i(() (jravelyi sp. n. the body-wall, the pallial 

 complex, the digestive system, the reproductive system, the nervous 

 system, the eyes and omraatophore, and the pedal gland, 



Arthropoda. 



a. lusecta. 



Inheritance in Euschistus.§ — Katharine Foot and E. C. 8trobell 

 have made experiments in crossing two species of Hemiptera — Euschistus 

 variolarim and E. servui<. The first of these has an exclusively male 

 character which is not present in E. servus, namely, a distinct black 

 spot on the male genital segment. It seems that the facts in regard to 

 the inheritance of this black spot are out of harmony with the 

 assumption that a factor for this character is carried and distributed by 

 definite chromosomes. Whatever determines the genital spot in 

 these hybrids, it cannot be an indivisible unit-factor. The authors 

 have not been able to harmonize their results either with the Mendelian 

 or with the blend type of inheritance. Castle's assumption of the 

 varying potency of unit-factors may perhaps help. 



Inheritance in Hemiptera. || — Katharine Foot and E. C. Strobell 

 have followed up their previous study of crosses between Euschistus 

 variolarins and E. servus. Dr. Eltringham, of Oxford, has discovered 

 that there is a marked difference in the length of the intromittent 

 organ in the two species, and this has afforded a valuable control for 



* Zoologist, xix. (1915) pp. 25-34 (6 figs.). 



t Amer. Journ. Auat., xviii. (1915) pp. 515-24 (6 figs.). 



: Records Indian Museum, xi. (1915) pp. 153-61 (4 pis.). 



§ Journ. Linn. Soc. (Zool.) xxxii. (1914) pp. 837-73 (7 pis. and 2 figs.). 



1[ Journ. Linn. Soc. (Zool.) xxxii. (1915) pp. 457-93 (7 pis.). 



