92 Ti^'ctity-scvciith .liiniial Meeting 



and some simple appliance arranged for excluding the light at the 

 union, or, if the lenses of the camera are good ones, they may be 

 left in and better results be thus obtained. The writer pursues 

 the latter course with better results than with the former. When 

 the mrcisocope is well focused the camera will be, no matter 

 whether the bellows be drawn out to the fullest extent or short- 

 focused, the only difference being- the size of the picture. 



From half a minute with a Welsbach gas burned to five min- 

 utes, or a little less with a coal oil lamp will be found within 

 reasonable range for time of exposure but this will have to be 

 determined by individuals by experience. 



Quick plates should be used, and Metol developer will be 

 found to be the most effective, giving a wide range, and being 

 especially good where the plate is under-exposed, very likely to 

 be the case where the embryo is sufficiently developed to move in 

 the egg or with fry while alive. 



In conclusion, I would say that the making of photo-micro- 

 graphs is not nearly so difficult as most people suppose and that 

 it can be readily mastered by calling a little perseverance and 

 patience into requisition. 



Mr. Whitaker: I want to say a word in connection with this 

 paper, as it seems to me to have great practical value in connec- 

 tion with the stripping of fish. I believe that strippers become 

 ultimately overconfident of their ability and become careless in 

 their work and need just such a correction as this examination 

 by the microscope will give. I think that the percentage of poor 

 ova is due very largely to this overconfidence and poor handling 

 of fish in spawning time. In a manual recently issued by the 

 United States Commission there is an excellent article about the 

 careless handling of fish in spawning operations. It appealed to 

 me to be a very just criticism. If is the rough handling, to a cer- 

 tain extent, that causes the large loss of spawning fish at that time. 

 This use of the microscope as applied by Mr. Stranahan seems to 

 open to the practical fish culturist a very wide field. It is greatly 

 to the credit of Mr. Stranahan that he has taken this w'ork up 

 in the way he has and I imagine in the next few years, if it is 

 pursued by others, a great deal of good will result from its use. 



Mr. Nevin: The way we keep track of our strippers is to 

 have our boxes numbered, a number being given each stripper, 

 and we keep track of his eggs; we send notice to the man if his 

 eggs are poor, and if he does not improve we drop him, 



