ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 185 



part the properties of the primitive mesenchyme (osseous medulla) 

 there arises a specially mobile variety, the myelocyte, and afterwards 

 the basophilous leucocyte. The latter, after diapedesis, may become a 

 fixed basophilous cell, probably a clasmatocyte. J. A. T. 



Structure of the Duodenum in Mammals. — F. Yillemin {G. R. 

 6'oc. Biol, 1919, 82, 1426-8). The duodenum in man and in those 

 mammals with the openings of the bile duct and pancreatic duct at the 

 same level (monkey, some rodents, carnivores, some herbivores) may be 

 divided into two portions, an upper, down to the apertures, and a 

 lower, beyond the apertures. The upper portion is dilated, with a 

 thick wall, with arteries from the hepatic only, and with Brunner's 

 glands. The lower portion is like a jejunal loop ; it receives branches 

 from the superior mesenteric ; it has no Brunner's glands. In the 

 mammals mentioned above Brunner's glands are of the mucous type. 



J. A. T. 



Types of Duodenum in Mammals. — F. Yillemix (6'. R. Soc. Biol., 

 1920, 83, 65-7). In the ox the bile duct opens far from the pylorus ; 

 the pancreatic duct below the bile duct at a relatively short distance 

 from it. In the pig the bile duct opens near the pylorus ; the pan- 

 creatic duct as before. In the rabbit the bile duct opens very near the 

 pylorus, and the pancreatic duct far from the pylorus at the end of the 

 duodenum. There are these three types. Brunner's glands, whether 

 mucous or mixed, extend to the opening of the pancreatic duct, but 

 never further, whatever be the distance of the aperture from the pylorus. 



J. A. T. 



Structure of Sphincter Muscles in Man. — A. Lacoste (C. R. Soc, 

 Biol., 1920, 83, 41-8). In sphincters with striped muscle-fibres, such 

 as those in the ureter and around the anus, each fibre has a thick 

 connective sheath, formed of connective and elastic fibres. The muscle- 

 fibres are surrounded by a plexus of elastic fibres, mostly perpendicular 

 to, or obliquely disposed to, the lie of the muscle-fibres. It is probable 

 that the intervention of the connective tissue between the fibres gives 

 the latter a " point d'appui " in the absence of fixed bony points. 



J. A. T. 



Plexiform Sphincters of Smooth Muscle in Alveolar Canals and 

 Pulmonary Acini of Mammals.— Gr. Dubreuil and P. LA]iiARQUE {C. 

 R. Soc. Biol., 1919, 82, 1375-7). The muscles of the terminal 

 bronchioles are continued on the alveolar canals by smooth muscle-fibres 

 which form a plexus. This plexus surrounds by its meshes the lumen 

 of the alveolar canals, forming a sphincter for each. J. A. T. 



Regenerative Growth of Striped Muscle-fibres after Traumatic 

 Lesion.— J. Nageotte and L. Guyon {C. R. Soc. Biol, 1919, 82, 

 1364-7). It was observed that a piece of glycerinated nerve introduced 

 between the two ends of a cut muscle was invaded by newly formed 

 striped muscle-fibres. J. A. T. 



