THE . 1 HERMAN NA TVRALIST 



when the eggs are ripe, (2) examination of the sea-water 

 to learn if oyster-larvae are present and in what stage, 

 (3) examination of natural or improvised objects in the 

 water to discover if young spat are already formed. The 

 first is not immediately determinative because of the long 

 period of development separating spawning and spat- 

 ting. The last is not very practicable because of the diffi- 

 culty of finding and recognizing the youngest spat before 

 the period is gone by for putting out cultch. The second 

 is the only practicable and conclusive method and its 

 efficiency is proportionate to the number, care and ac- 

 curacy of the observations. Its success will increase with 

 experience. 



This method makes use of the colossal number of larva- 

 lavishly provided by nature to offset the exigencies and 

 accidents of life and insure a reasonable chance of keep- 

 ing up the stock. I believe that all the larvae an army of 

 men could raise up and turn into the sea would not ma- 

 terially alter the number of successful individuals in the 

 set of spat. But on the other hand a few culturists could 

 enormously increase the chances for a successful catch 

 by spreading an abundance of suitably prepared cultch 

 at the proper time and place. 



In the paper of 1909 I have described the method of 

 obtaining plankton, the appearances and measurements 

 of the oyster-larvae to be recognized, the time of the year 

 to begin making observations. In the paper on 1 'Bivalve 

 Larvae" I distinguish in sizes, shapes, colors, the com- 

 monly occurring associates of the oyster-larvae which 

 might be taken for the latter. In the present paper, after 

 long reflection, I suggest a practical application of the 

 knowledge acquired. 



I should not omit to mention that the paper of 1910 

 connects the larva, through the youngest microscopic 

 spat, with the macroscopic spat of fishermen and finally 

 with the adult. Similarly in 1909 L performed extensive 

 artificial-fertilization experiments, while at Shediac, 

 Caraquette and Malpeque, in order to connect the small- 



