270 s. GOTO; 



The permanent communication of the stone-canal with the nxial 

 sinus above described has been clearly recognized and stated by Bury 

 ['95, p. 67] and MacBride ['93 & '95, p. 851], and Durham ['88] 

 has also des-^ribed such a, direct connection in CrihreUa oceUata. The 

 latter, however, evidently regards the occurrence of such a communica- 

 tion as rather exceptional; and the statements of the majority of 

 writers on asterid anatomy are against it. Hoffmann ['7o, ]). K^] 

 among older writers has, indeed, asserted, from the result of injection, 

 a connection of the blood system Avitli external water by means of the 

 axial sinus ; but this does not prove anything as to tlie communication 

 of the latter with the stone-canal. Hamann, as well as Vogt and Jung, 

 has also described a communication between the axial sinus and the 

 surrounding cavities. According to Hamann ['85, p. 51] there is a 

 direct connection between the enteroc<i'l and the axial sinus at the 

 point, " wo vom Cliromatogenorgan Teile aus dem schlaucliftirmigen 

 Kanal heraustreten, von welchen die Gelasse zum Mitteldarm abgehen, 

 und diese Teile nicht von Fortsetzungen der Kanalwand umkleidet 

 werden, sondern dieselbe einfach durchbrechen." Vogt and Jung ['88, 



p. 608, French edition p. 600] have described a direct connection 

 between the axial sinus and the water-vascular system, and this con- 

 nection takes place, .according to thes^' authors, by numerous fine 

 openings. It must be remarked here that the method of injection is, 

 to judge from a comparison of the statements of other-writers with the 

 results of my own observations, in which I have traced the civities 

 through all stages of their development up to the complete star, very 

 unreliable as to the question of communication between different 

 cavities, unless indeed it be accompanied by exact microscopic observa- 

 tions of serial sections; as a communication might take place by way 

 of the meshes of the connective tissue where there is naturally none 

 at all. In none of my sections have I observed sucli openings as are 

 described by Vogt and Jung. 



