clxiv Journal of Comparative Neurology. 



The Application of Methyl Blue to Mncous Membranes. 1 



Portions of the tissue to be studied, excised from an animal just 

 killed, were placed in a i to 2 per cent, solution of methyl blue. The 

 color penetrated much more rapidly, especially with cold blooded an- 

 imals, if warmed to 30 deg. C. A slight addition of ammonium car- 

 bonate to the solution increased the sharpness of the effect. The 

 color was fixed in concentrated ammonium picrate, remaining in the 

 solution for several days. The preparations were then immersed in a 

 mixture of glycerine and distilled water in which they may be left for 

 several months without injury. Free, very fine termini were found 

 uniformly distributed over the mucous membrane of the bladder. 

 The mucous membrane of the vagina is more richly supplied with 

 nerves than that of the uterus. Nerve termini were traced (1) in the 

 mucosa, (2) in the muscular layer, which Is quite as richly supplied as 

 the preceding, (3) intra-epithelial nerve termini (?), (4) vascular nerves 

 about the arteries, veins and capillaries. The termini are usually 

 free without knobs. Strict anastomoses were not conclusively demon- 

 strated. 



The Crossing of the Respiratory Paths in the Cord. 2 



Seven experiments on dogs and rabbits operated upon under an- 

 aesthetics afford the most convincing proof of the following conclu- 

 sions : 



(1) The respiratory paths ascend in the lateral columns of the 

 cervical cord ; (2) the stimuli from the bulbar centres can excite (un- 

 less dyspnoea persists) the phrenic centre of the other side ; (3) this 

 decussation occurs at the level of the phrenic centre ; (4) such a de- 

 cussation does not occur in the cord between the phrenic centre and 

 the calamus scriptorius. 



To these anatomical discoveries the author appends the following 

 hypothetical considerations : (1) The respiratory excitation descends 

 in the lateral columns and ends in numerous ramifications at the levil of 

 the phrenic nidulus of the same side. (2) The dendrids of all of the 

 phrenic cells may be divided into two groups : one group containing 

 many dendrids which lie in contact with the terminal ramifications of 

 the descending lateral respiratory fibres ; the other, containing rela- 



^alischer, O. Ueber die Nerven der Harnblase, des Uterus und der 

 Vagina. Math. u. naitirw. Mitth. Akad. Wiss. zu Berlin, H, 7, July, 1894. 



2 PORTER, W. T. Ueber die Kreuzung der herabsteigenden Athmungserre- 

 gung im Niveau der Phrenicuscentren. Cent. f. Physiol., VIII, 7, 1894. 



