32 



HA RD WICKE'S SCIENCE- G OSSIP. 



DEVELOPMENT OF FROG-SPAWN. 



IN reference to an article which appeared in the 

 June number of Science-Gossip on the de- 

 velopment of the tadpoles of the common frog (Rnna 

 temporaria), I forward the following notes from my 

 pocket-book, which may be interesting as comparing 

 dates of development. 



I took frog-spawn from a pond at Ashleigh, in 



bottle was as lively as ever, though the water was 

 perfectly warm. 



In my pocket-book is a memorial inscription, " To 

 the memory of ten tadpoles who died at the age of 

 one month and a day. They lived a short and merry 

 life, and died honourably, martyrs to the cause of 

 science." 



Not to be daunted, however, in my pursuit of tad- 

 pole-lore, I obtained some new specimens in exactly 



Fig. ii. — Tuesday, March 23, 1886. 

 Frog-spawn. 



Fig. 12.— Saturday, March 26. First 

 change noticed. 



Fig. 13.— Sunday morning, March 27. 

 Very occasional movement. 



Fig. 14. — Sunday evening, March 27. 

 Heads and tails brought together, 

 terrific struggle after freedom. 



1 I c 



Fig. 15-— Monday, March 28. 

 Several free, but quiet and 

 stupid. Entirely black. 



Fig. 16.— Friday, April 23. Very lively. Black, spotted with gold. 



Fig. 17. — Monday, May 3. Eyes visible from 

 under side of tadpole. 



Fig. 18. — Thursday, June 3. Beautifully splashed with gold, eyes not 

 visible from under side. 1. Upper side. 2. Under side. 2a. Blood-red 

 band. 3. Side view. 



Wiltshire, on March 23rd of last year. The follow- 

 ing sketches, life-size, denote the changes as I 

 observed them, the spawn being placed in a large 

 glass preserve-bottle. 



There occurs a break in my notes, occasioned by 

 the untimely death of my tadpoles. Thinking that 

 they would enjoy the sun, I placed the bottle on a 

 sunny window-sill with the deplorable result, that the 

 tadpoles were cooked. 



A Lymnaa vtimtta which had occupied the same 



the same stage of development as my late lamented 

 proteges. They were much wilder and more active 

 than the others (alas ! perhaps in better health) and 

 I had great difficulty in drawing them with any 

 accuracy. 



Since the accident I kept the tadpoles out of doors 

 in the shade, only feeding them by changing the 

 water every other day. As their development was 

 slow, I did not again sketch them for a month. 



They were then in size as drawn at Fig. 18. 



