374 Mr. E. Atkinson on 



An interesting fact illustrating the great vitality these ova 

 possess is that a small quantity of the original stock of mu'l 

 given to a friend had by him been put away in a pill-box and 

 foro-olten. Nine years after it turned up in his desk ; little 

 expecting any result, he placed it in a small glass jar and 

 added water to it, but a fortnight later a single specimen of 

 the Esther ia gihoni, the rarest and most beautiful form, made 

 its appearance. 



Another friend, a clergyman in the South of England, to 

 whom I gave a portion of the mud, and who had continued the 

 process of alternating the wet and dry season for twenty-four* 

 years with unvarying results, removed to Tunbridge Wells. 

 During the change of residence the globe containing his dried 

 mud was accidentally broken and thrown with other rubbish 

 at the back of a rockery in the garden. Next spring its 

 owner discovered it, to his dismay, in its ruined condition ; 

 but finding that the mud still remained adherent to the main 

 fragment, he transferred it to a new globe of water, when, to 

 his surprise, three weeks later his old friends appeared, as if 

 nothing had happened, although the winter had been very 

 severe and the broken globe was frequently buried in snow ! 



In 1S96 — an interval of thirty years having elapsed since 

 I lost the succession of crops in my own aquarium — I availed 

 myself of a friend's visit to Jerusalem to obtain a new supply 

 from the same spot ; and both last year and this I have had 

 the pleasure of renewing my acquaintance with the now 

 familiar forms. Together with my friend Mr. H. Crowther, 

 F.R.M.S., the present Curator of theLeeds Museum, I have had 

 six jars under observation. Thcsame forms described by Baird 

 appear regularly each season, especially the smaller species 

 (Daphnia and the Cyprids), in every jar, whereas I observe 

 that the larger forms (Estheria and Branchipus) were often 

 one or both absent from one jar while numerous in another, 

 which seemed to suggest that their ova did not in every case 

 retain their vitality so well as the smaller kinds, or else that 

 the ova of the larger species were less equally distributed, 

 lying, as it were, in nests in one fragment of the mud and 

 not in another ; and, indeed, this seems to be the more likely 

 explanation. 



The following is Dr. Baird's list : — 



* I learn from my friend that after 1884, " in the spring of which year 

 all the forms seen before came to vigorous life, the mud remained care- 

 fully put away until given in 18U4 to another friend," who, after the ten 

 years' interval, again restored them to their annual activity, and this is 

 maintained. 



