1897] MICROSCOPICAL JOURNAL. 341 



on both sides of the Atlantic. Observers are beginning 

 to trace the connection between the presence of micros- 

 copical organisms and the abundance of fish in our lakes 

 and valuable comparisons have been made between the 

 stomach and intestinal contents of fishes and the organ- 

 isms found in the water where the catches were made. 

 This work is of very great importance and should be 

 vigorously pursued by our fish commissions. To be of 

 the greatest value it should extend well over the country 

 and include lakes and ponds sufiiciently different in char- 

 acter to enable one to determine the laws governing the 

 nature and distribution of the plankton in various climates 

 and under various conditions. The study ought not to 

 be carried on spasmodically, as, for instance, during the 

 short vacation of some college professor who generously 

 gives his time and talents to the cause, but should be 

 undertaken seriously and continued throughout the whole 

 year. Only in this way can we obtain the data necessary 

 for a complete understanding of the subject. 



Since water-works managers are equally interested in 

 the microscopical organisms found in surface waters, and 

 up to the present time have been responsible for most of 

 the work done upon the subject, it might be possible for 

 fish commissions, boards of health, water-works super- 

 intendents, and others interested, to work together 

 according to a definite concerted plan, sending their 

 results to some central commission or committee for com- 

 parison and study. Such an extended biological study 

 taken in connection witli meteorological records and 

 observations upon temperature, transparency, etc., of the 

 water would be of very great value. And it would seem 

 that we have little excuse for neglecting to cultivate this 

 fruitful field of research. Vast numbers of microscopical 

 examinations are now being made. During the past eight 

 years more than 40,000 have been made in Massachusetts 

 alone, and the rajjid growth of the new science of sanitary 



