47 



with bell-shaped ends not unlike the ends of the old-fashioned 

 bell-pulls of former days. It has been ascertained that these 

 are suckers, if I may use the expression, by which the young 

 Ascidian ultimately fastens itself to stones or seaweeds when 

 it settles down to a quiet life and a permanent residence. 

 These appendages are remarkably well shown in some of the 

 embryos under notice (fig. 3, h). Three are always very 

 distinct, and in some specimens three or four smaller ones 

 are present. It is difficult to understand why they are there, 

 knowing as we do that these embryos can never enjoy a free 

 swimming existence. As the embryo grows we see these 

 appendages lengthen out, and they may be seen traversing the 

 inter-ascidian tissue in all directions, and can be sometimes 

 traced for considerable distances. I suspect that these cords 

 are hollow, and that they form a network of communication 

 between the members of the colony. I must, however, wait for 

 chance to put in my way a few living specimens before this and 

 many other questions can be worked out. 



In all the embryo specimens there is a projecting portion of 

 ill-defined tissue (fig. 3, «), which is probably nervous, and 

 in it are embedded behind each other two distinct masses of 

 pigment, which I take to be rudimentary ej^es ; but I do not 

 notice any ocelli between the tentacles of the adult animal. 



The digestive organs, nervous system, and organs of circula- 

 tion are not so distinct in an}^ of my specimens as to enable me 

 to note more than that they appear to have a general resem- 

 blance to those of the larger Ascidians. Some specimens I 

 began to prepare yesterday will probably enable me by means 

 of differential staining to get a step onward to more minute 

 details. At present I believe the intestine terminates in a 

 tube passing a short way upward by the side of the pharynx 

 (fig. 3, e), opposite to that where the longer tube already 

 described is seen. I have not been able to trace how it com- 

 municates with the exterior. 



I believe this Ascidian comes nearest to the family of 

 Botryllida\ but to all appearances it is free swimming. 



EXPLAXATIOXS TO PlATE I. 



Pig. 1. a, Pits in external test ; h, mouth ; c, cap ; d. tube run- 

 ning up side of pharynx ; e, supposed end of intestine ; 

 /; body of Ascidian. 



Pig. 2. Enlarged view of cap. a, Mouth-tentacles ; J, vibratile 

 tentacles. 



Pig. 3. a, Eye and otolith; h, suckers; c, tail; J, digestive 

 or^^ans in formation ; e, birdcage-like pharynx in for- 

 mation. 



