tkan.sact:ons of section d. — dept. anatomy and physiology. 577 



3. Note on tlie Structure of the Muscular Tissue of the Leech. 

 By T. W.' Shore, Jan., B.Sc. 



After detailinfj his observations on the fresh muscle-tissue of the leech, and 

 describing the action of reagents, the author sums up as follows: — 



1. The muscle- tissue of the leech consists of elongated tubes with two coats — 

 the sarcolemma and contractile layer — the inner surface of which is irregular, and 

 gives rise to apparently granular contents. 



2. In the living condition it is uustriped. 



3. There are no nuclei, and the contents are a colourless serous fluid. 



4. Transverse striation may be produced post mortem as the result of three sets 

 of changes : — 



(rt) Regular arrangement of the papillte on the inner surface of the con- 



ti'acttle layer. 

 (6) Foldings of the surface of the sarcolemma. 

 (r) Splitting into segments of the contractile substance. 



5. The contractile substance coagulates, forming myosin, which subsequently 

 contracts. 



6. The rapidity of and mode of contraction give rise to varying appearances of 

 fissures, striation, &c. 



He then passes on to a discussion of the bearing of these results on other con- 

 siderations, and finally suggests a new theory as to the structure of striated muscle- 

 tissue. 



4. On the Kidneys of Teleostei. By W. Newton Parker. 



In a paper read last year at the British Association, the late much-lamented 

 Professor Balfour showed that in certain adult Teleostei, as well as in Lepidosteus 

 and Acipenser amongst the Ganoids, the so-called 'head-kidney,' or pronephros, 

 contained no uriniferous tubules, but was composed entirely of highly vascular 

 lymphatic tissue. He therefore considered it probable that there were no func- 

 tionally active remains of the pronephros in the adults of either of these groups. 



The author of the present paper, in following up these investigations, finds that 

 in some Teleostei the so-called ' head-kidney ' has precisely the same structure as 

 the rest of the kidney, or mesonephros. He nevertheless holds to Balfour's view 

 as to there being no functionally active remains of the pronephros in the adult, and 

 explains the above cases by siipposing that the mesonephros has grown forwards in 

 i'ront of the air-bladder, where there is most room for it, so as to take the place of 

 the larval pronephros. That this is not improbable is shown by the gi'eat variation 

 in the form and position of the mesonephros in difterent species of fishes. 



5. On the -presence of a ' Tympanmn ' in the genus Raia. 

 [ By George Bond Howes. 



The author regards a fenestra (long known to exist) in the roof of the audi- 

 tory capsule of the genus, and its adjacent parts, to be a modification of what is 

 seen in other species, which is correlative of the compression from above downwards 

 ■ undergone by it, resulting in the formation of a 'tympanum' physiologically fore- 

 shadowing the essential process involved in the elaboration of the auditory organ 

 of the higher forms, the real bearing of which has hitherto escaped notice. 



6. On some Toxic Conditions of tJie Blood, illustrated hi/ the action of Hydro- 

 cyanic Acid. By Thomas S. Ralph, M.B.C.S. 



The author satisfied himself of the occurrence of amyloid bodies in the blood, 

 a blue reaction being produced by the administration of hydrocyanic acid, and 

 1882. p p 



