748 REPORT OP COMMISIIONER OF FISH AND FISHERIES. 



If the eggs are in a thick layer on the bottom, only a few, cc| 

 lively, develop, and this fact consequently necessitates the use ( 

 low jars, or dishes, having a large bottom area, during this par 

 process, or else some other form of apparatus which will produce tlj 

 desired result, viz, freedom from pressure. During the past sej 

 accomplished this end, approximately, by placing the eggs wli 

 free of debris and unripe eggs or excessive spermatozoa, in sou] 

 or large platters ; at Fair Haven I used the largest dishes I coi 

 chase and with good results. The principal point is not to ov< 

 the eggs ; it is better to err on the side of too much caution, sa( 

 some of the eggs if necessary, rather than in the attempt to ^^ 

 run the risk of very many failing to develop. I also devised I 

 method which gave fair results, and which appears susceii« 

 improvement. It consisted of a small glass funnel holding i 

 pint, and having a jet of air through a narrow orifice in the 

 The water containing the eggs was placed in the funnel and 

 stream of air, as little as possible, was forced up through the ap 

 The eggs by thiis means were kept constantly in motion, risiu 

 middle and sinking along the sides of the funnel. We got v( 

 results from this appliance but I am not prepared to say tha 

 ceeded very much better than the platters. A slight improv( 

 the form of the funnel would add to its efficiency ; the nearer i 

 conical its interior form the better. 



We did not find it necessary to add any water during the pi 

 segmentation, but having once placed the eggs in the plates oi 

 we allowed them to remain undisturbed until the first swimmii 

 was reached. It is very important that when using the plates 

 preparations for operations subsequent to the time of arriva 

 swimming stage should be completed several hours before th 

 occurs. The plates must not be moved nor the eggs disturbet' 

 will be impossible to avoid carrying into the secoud receptac 

 undeveloped eggs. In using the cone, a rest due to cessation t^ 

 jet for one hour or more was allowed, before any attempt to 

 the swimming embryos was made. 



Attention is called to Brooks' description of the developmcT, 

 egg, in order that the significance of this latter point may be app^ 

 The embryo swims at the surface but a comparatively short tii^ 

 large numbers of eggs never reach this stage and the swimming^ 

 must be separated from them before the disintegration of th 

 renders the water so impure as to insure the destruction of tl, 

 This removal is not always easy of accomplishment, but we si 

 partially, by using two plates. In one was placed the egg, 

 segmentation, with water enough to nearly fill it. The seco 

 was arranged under the first, so that any overflow from the latt 

 fall iuto it. After the embryos began to swim the first plate cc 

 them was overflowed, drop by drop, by me^ans of a minute stream 



