300 SUMMAKY OF CURRENT RESEARCHES RELATING TO 



border. Later on the two primordia fuse into a median organ in the 

 line of the longitudinal axis. Finally the unpaired median organ 

 divides into two gonads, which descend into the coelom and acquire a 

 peritoneal investment. 



Development of Adhesive Organ of Sturgeon.* — A. M. Sawadsky 

 has studied the development of the non-functional larval adhesive organ 

 of Accipmser rutJwius. It is endodermic, and is formed from the 

 anterior wall of the oral fold. It gets turned outwards by the forward 

 growth of the head, and the ends of the cells that were towards the 

 lumen of the gut become directed externally. The mouth-cavity seems 

 to be due to the union of two prte-mandibular gill-pouches, and the 

 strongly growing dorsal wall forms the adhesive organ. 



Development of Ctenoid Scales. f — A. Hase has studied the de- 

 velopment of these scales, e.g. in some Pleuronectids, during the first 

 year. He shows that the ctenoid scale is a further evolution of the 

 cycloid type, that the teeth at the posterior margin have no independent 

 nature and are not comparable to the teeth of placoid scales, and that 

 there is a definite relation between the rings of growth on the scale and 

 the teeth. 



?*• Histology. 



Protoplasmic Bridges.^ — F. K. Studnicka proposes the term 

 " plasmodesms " for protoplasmic strands which unite the protoplasm or 

 endoplasm of adjacent cells in cases where there are no intercellular 

 gaps ; and " cytodesms " for protoplasmic strands which unite entire 

 cells separated from one another by intercellular gaps. Under these 

 main divisions he proposes many minor ones. 



Connexion between Muscle and Tendon. § — 0. Schultze gives an 

 account of the observations which have convinced him that there is a 

 direct connexion, amounting to continuity, between muscle-fibrils and 

 tendon-fibrils. 



Structure of Mammalian Red Blood Corpuscle. || — V. Schilling- 

 Torgau finds great complexity in a typical mammalian erythrocyte. 

 There is a well differentiated central apparatus, with a " lens," a micro- 

 centrum, a capsule-body, a " blood-plate " or " plate-nucleus." The 

 cytoplasm shows a radiate structure with htemoglobin in the meshes and 

 some polychromatic substances disposed on the rays. There is a com- 

 plicated ectoplasmic outer zone, and possibly a membrane. 



Basilar Membrane of Rabbit's Cochlea. IF — E. Vasticar describes 

 six distinct layers : (1) a structureless layer ; (2) a hyaline layer ; 

 (3) one or more layers of large basilar fibres ; (4) a hyaline layer finely 

 striated ; (5) a layer of amorphous substance ; and (6) a connective 

 tissue envelope. 



* Anat. Anzeig., xl. (1911) pp. 856-78 (1 pi. and 18 figs.). „ "l"' 



\ t Anat. Anzeig., xl. (1911) pp. 337-56 (28 figs.). 



X Anat. Anzeig., xl. (1912) pp. 497-506. 



§ Arch. ]\Iikr. Anat., Ixxix. (1912) pp. 307-31 (3 pis.). 



II Anat. Anzeig., xl. (1911) pp. 289-302 (19 figs.). 

 ,f Comptes Rendus, cliv. (1912) pp. 391-3 (1 fig.).^ 



