104 FLANARIA ARETHUSA. 



period exceeding a year, and though I have 

 removed many from their natural abode at 

 all different seasons, I never could be sen- 

 sible of finding either eggs or living young. 

 Not long ago, however, I concluded that 

 the fact was at last ascertained. In a ves- 

 sel containing these planariae, and little else 

 than pure water, several rows of small 

 bright yellow eggs were observed, each row 

 being in a straight line, and consisting of 

 about twenty-four. The like was found, un- 

 der similar circumstances, in another vessel; 

 and I anxiously watched the exclusion of 

 the expected young, for the eggs were in 

 no respect dissimilar from what might have 

 been produced by planariae, except in size : 

 and besides there not being any general 

 rule in this particular, their smallness was 

 a satisfactory reason why they had been 

 detected with so much difficulty. But soon 

 after, the same was exhibited in a third 

 vessel, certainly containing no planariae, 

 which immediately betrayed the fallacy ; 

 and on more minute investigation, the eggs 



