422 



jection be thrown into the long ciliary arteries while the 

 collateral venous channels are tied to increase the pressure, 

 or, -what conies to the same thing, the tension in the anterior 

 chamber be diminished by ])uncture, fluid may be forced 

 through the superficial sclerotic veins into Schlemm's canal, 

 and thence into the anterior chamber. The occurrence of 

 blood in this canal in the eyes of persons who have been 

 hung, and under other circumstances, which have caused it 

 to receive the name of sinus venosus, are explained by 

 ScliAvalbe as consequences of excessive venous tension. It is, 

 therefore, probable that the communication between the 

 anterior chamber and the venous system is regulated by 

 oalance of pressure, and not by any system of valves. 



The canal of Petit was sometimes, though not always, 

 filled by injection from the anterior chamber. This was 

 found to depend really upon certain small slit-like openings 

 close to the border of the crystalline lens by which the canal 

 communicates with the posterior chamber, and from this 

 chamber it was very easily injected. The success of in- 

 jections from the anterior chamber depends on altering the 

 convexity of the eyeball and the position of the lens. (By 

 j)OSterior chamber is understood an annular space between 

 the iris and the lens, closed centrally by the contact of the 

 front surface of the lens Avith the margin of the pupil.) 



Lympliatic Spaces in the Brain. — Oberssteiner (' Sitzungs- 

 berichte der AViener Akademie,' Math. Naturwiss. Classe 

 1870, p. 57) describes lymphatic spaces in the brain, not 

 only surrounding the blood-vessels, as described by Robin 

 and His, but also round ganglionic cells. These spaces con- 

 tained lymph cells, were in communication with the peri- 

 vascular spaces, and susceptible of injection from these. 

 Similar channels were also seen under the epithelium of 

 the ependyma of the cerebral ventricles of the Frog. 



Nerve terminations in the Tongue. — The structure of the 

 tongue is the subject of two papers in M. Schultze's 'Archiv.' 

 Hans V. Wyss (vol. vi, p. 237) has repeatedly studied the 

 tongues of men and mammalia, and describes the goblet- 

 shaped or bud-shaped organs originally discovered simulta- 

 neously by Schwalbe and Loven (Schultze's ' Archiv,' IV, 

 9() .and 154). In the human tongue one papilla circum- 

 vallata may contain 400 of these structures, arranged in five 

 or six superimposed circular rows. The organs themselves 

 are imbedded in the epithelium, and project slightly beyond 

 its surface. They are composed of two kinds of cells : the 

 coveringor protective cells, which are placed outside; and the 

 bacillary cells (sensory cells of F. E. Schulze), which are pro- 

 tected by these. The former are epitheloid structures, arranged 



