540 SUMMARY OF CURRENT RESEARCHES RELATING TO 



The author uses three arguments showing that it is improbable that 

 the present musculature of the eye in Acanthias is the primitive one. 

 Two stages in the phylogenetic evolution are hinted at by the ontogeny,. 

 ■ — (1) a stage where if any eye musculature existed it was furnished by 

 the anterior somite, and (2) a stage at which four radially arranged 

 muscles moved the eye. 



Notes on Development of Liver.* — G. Hunter gives the results of 

 a number of observations on the development of the liver in Urodela, 

 chick, hare, man, &c. He considers the origin and morphology of the 

 primary hepatic cylinders, of the bile capillaries and ducts, and of the 

 blood-corpuscles - and the vascular channels. From the numerous 

 erythroblasts seen in the sections at all stages of development, it is 

 impossible to come to any other conclusion than that the liver is the 

 chief seat of blood formation during embryonic life, and perhaps also 

 for some time after birth. 



Development of Ventral Pancreas in Lacerta muralis. f — Ch. 

 Tecqmenne finds that the pancreas in this lizard arises from two dis- 

 tinct lobes, one distal, the other proximal. The former is in relation 

 with the spleen and may be called juxta-splenic ; it is ontogenetically 

 older, and is wholly a dorsal pancreas. The proximal mass may be 

 called juxta-choledochus, for it has a mixed origin, partly from the 

 dorsal pancreatic outgrowth and partly from a ventral outgrowth. Be- 

 tween the two portions and uniting them, but free from all pancreatic 

 tissue, there extends a long portion of the duct of the dorsal pancreas. 

 Thus, in general, the development of the pancreas in Lacerta muralis 

 is similar to that described in other reptiles by Gianelli, Glas, Choron- 

 shitzky, and Laguesse. 



Comparative Anatomy and Embryology of the Malpig'hian 

 Bodies.^ — P. T. Herring sums up a useful general discussion of this 

 theme in the following general conclusions. There is an analogy be- 

 tween the organs of excretion of Craniata. We observe that the author 

 does not, even with his data, say that there is a homology. The simplest 

 form of Malpighian body is found in the pronephros during embryonic 

 life. It is at first part of the peritoneal cavity, and the pronephros at 

 that stage shows a close resemblance to the organs of excretion of 

 Amphioxus. Later on, the glomerulus appears in a specially formed 

 part of the peritoneal cavity. In the mesonephros, a peritoneal con- 

 nection is usually present at first, but becomes imperfect. In the rueta- 

 nephros, according to the author, the cavity ot Bowman's capsule may 

 be considered to correspond to part of the body-cavity specially dif- 

 ferentiated for purposes of excretion. The development of the Mal- 

 pighian body lends support to this view, especially if we are to consider 

 it, as Braun does, as formed from the peritoneal epithelium. The layer 

 of endothelial cells lining Bowman's capsule corresponds to the lining 

 cells of the general peritoneal cavity, and helps to complete the re- 

 semblance. 



* Proc. Scot. Micr. Soc, iii. (1901) pp. 114-21 (4 pis.). 

 + Anat. Anzeig., xxi. (1902) pp. 278-92 (3 figs.). 

 X Proc. Scot. Micr. Soc, iii. (1901) pp. 109-13. 



