DEVELOPMENT OF THE TADPOLE. 27 



orifice of the tube, and by the force of the stream flowing 

 through it were washed over into the exit tank. The tube 

 was now made in the form of a small funnel at the end in 

 the water, and this being covered with muslin offered a large 

 surface for the passage of the liquid, and at the same time prevented 

 the escape of the animals, whilst thus affording a soft cushion 

 for any of them, whose curiosity had led them sufficiently 

 near to be forced against it with a power greater than their 

 own efforts of resistance. There they remained fast prisoners, but 

 quite unhurt till the stoppage of the stream enabled them to swim 

 off again, apparently with great rejoicing. The fresh water was 

 carefully poured in by means of a long funnel, so as not to injure 

 these delicate living morsels, but as they grew stronger a gentle 

 stream was allowed to flow in from the tap. 



As before mentioned, the first tadpoles commenced to eat on 

 March 30th, or rather to open and close their mouths as though 

 in the act of eating, and being curious to know the nature of their 

 food, a careful microscopical examination of the water in which 

 they lived was undertaken, with the result that it appeared crowded 

 with minute nucleated corpuscles, varying from the size of pus 

 globules to three or four times that size. 



As nothing more substantial could be found in the water, and 

 as the embryos continued to thrive and get more vigorous day by 

 day, the only conclusion which could be arrived at was that they 

 obtained their food from these minute particles floating through 

 the water, and apparently (derived from the decomposition of the 

 transparent envelope which had previously surrounded the eggs, but 

 which had now almost disappeared. That this is capable of 

 affording nourishment may be considered certain from its compo- 

 sition being not dissimilar to that of gelatinous substances generally. 



On the I St of April, the little creatures were tempted with 

 portions of fresh liver, but although they soon discovered its 

 presence and smelt around it they did not commence to eat, but 

 seemed to delight in swimming near and in the bloody water 

 exuding from it. Whether on this day they obtained any nourish- 

 ment or not from this liver, or the exudation from it, I am not 

 able to state ; but next morning many of them were evidently 

 sucking and enjoying the juices derived from the meat. It must 



