62 W. FELL WOODS ON THE RELATION OF 



found, sometimes in the ovary and sometimes in the tube, I seemed 

 shut up to discard the idea that this frequently branched and ex- 

 tremely lengthy tube could be other than a legitimate organ of 

 the Cockle, and to suggest the theory I still advanced on the 4th 

 November last, at a meeting of the Eoyal Microscopical Society, 

 that this Bucephalus might be the larval form of the Cockle. 

 There is another consideration which may strengthen my position 

 (though its contrary would not necessarily invalidate it), viz., that 

 if this be a parasite we onght certainly to find it when the male 

 element of the Cockle is visible in the gland, and, though I cannot 

 of course affirm that it may not be so found, I doubt if I have 

 observed it. 19 



Moreover, when in May, 1873, Dr. Moore became interested 

 in this creature, his examination of Cockles, which I sent him 

 from time to time, led him to the same conclusions. 



The observations which I have now laid before you are all taken 

 from notes made, from time to time, by me prior to the last 

 mentioned date ; and the two series of observations are therefore 

 independent and corroborative. 



But I must now adduce two recent observations of great interest, 

 inasmuch as not only do they confirm the fourth and fifth states, 

 but one of them offers a sixth still more valuable. The first was 

 on the 6th and 7th of the present month. The tube was most dis- 

 tinctly branched, composed of two layers, and in other ways as 

 usual ; in removing a portion I obtained also a large piece of 

 racemose structure, quite unlike the tube, 20 and which it was not 

 possible either to disentangle from it, or positively to trace to a 

 junction with it. With lens or under microscope, it proved to be 

 two or three of the usual bunches of lobules. Both tubes and 

 sacs contained similar eggs variable in size, 21 the tube seemingly 

 having a larger proportion of the larger size. The eggs differed 

 somewhat from those usually seen in the sacs, in that their 

 capsules, if they had them, were contracted, or not yet enlarged, so 

 as scarcely to show any zona pellucida. They had but little yelk, 

 and in fact were \v._ an early stage. 22 Lifting a portion of the tube 



19 This argument must be abandoned, as on May 3rd I found a Cockle having 

 both the tube with Bundry stages of Bucephalus and sacs containing sper- 

 matozoa. 



20 Figs. D 1 and 2. 



21 April 6 and 7, 1875. Figs. F 1 to 3. 



22 Compare Cockle eggs, no tube, April 7, 1875. Fig. E 5. 



