320 p. HERBERT CARPENTER. 



officers of which as well as to Mr. Hnnt^ my best thanks are 

 due for their efforts on my behalf. 



I had at first simply intended to incorporate my observations 

 in the general discussion of the vascular system in the " Chal- 

 lenger" report. But the subject has also been taken up by 

 Professor Perrier, whose views respecting the vascular system 

 of the Crinoids are entirely different from those of Ludwig and 

 myself; and some of the conclusions at which he has arrived 

 are of such a startling and bewildering nature that I am 

 anxious to discuss them at once, so as to clear the way for the 

 general summary of the question which will appear in the 

 report. 



Perrier's observations, like so many of his previous ones, are 

 recorded in a brief note of three pages in the ^Comptes 

 rendus,'^ and hardly any reference is made to those results of 

 other workers, with which his own conclusions are in direct 

 conflict. In fact, as will be seen immediately, some of his 

 most recent statements are absolutely irreconcileable with 

 those contained in his last note;^ while others are made in 

 such a guarded manner that it is difficult to understand 

 whether he really means all that his words imply. 



Let us consider, first of all, what he says about the primary 

 water-tube and water-pore in the cystid phase, the relations of 

 which have been so well described and figured by Ludwig.^ 

 According to the German author, the primary water-tube 

 depending from the water-vascular ring opens below into a 

 section of the body-cavity that is cut off from the rest by a 

 band of connective tissue ; while the primary water-pore which 

 pierces the oral plate, opens into the same space. The course 

 of both water-pore and water-tube is somewhat curved, but the 

 two organs are not so absolutely continuous as to form one 

 tube. Perrier, however, tells us that this single curved Avater- 



' " Sur le developpement; des Comatules," ' Coniptes rendus,' tome xcviii, 

 No. 7, February 18th, 1884, pp. 444—446. 



• 2 « Sur I'organisation des 'Crinoides," ibid., t. xcvii, No. 3, July 16th, 1883, 

 pp. 187—189. 



3 Op. cit., p. 39, Taf. xii. 



