THE DEVELOPMENT OF LAMELLIBRANCHS. 315 



a gallon ; two or three dipping-tubes, or glass tubes six 

 or eight inches long, open at both ends, but with one end 

 drawn out to a fine point ; a small glass or rubber siphon 

 for drawing the water out of the beakers. For tracing the 

 development *of the eggs, a microscope, magnifying at 

 least one hundred diameters, and half a dozen glass slides 

 and thin glass covers are wanted. 



After the specimens have been opened, and at least one 

 ripe male and one ripe female found, cut off the mantle 

 lobes and gills of the male with the scissors, close to the 

 visceral mass, and tear them out with the forceps and 

 throw them away. Cut around the adductor muscle with 

 the scissors, so that the visceral mass may be lifted out of 

 the shell and transferred to a small saucer or to a watch- 

 crystal. Holding the visceral mass with the forceps, cut 

 out with the scissors as much as possible of the digestive 

 organs and liver, and throw them away, and then chop up 

 the reproductive organs with the scissors, picking out and 

 throwing away any fragments of the liver, digestive organs, 

 mantle or gills which may present themselves. In order 

 to have the young thrive, the water must be kept free from 

 fragments of the various organs of the adult, as these 

 would soon decay and destroy the embryos, and it is there- 

 fore important to remove them as completely as possible. 

 After the mass has been chopped up as fine as possible, 

 fill up the watch-crystal with fresh sea-water, stir it up, 

 and then allow it to run into one of the smallest beakers, 

 which has been nearly filled with sea-water. As the 

 water runs out of the watch-crystal, be careful to allow as 

 few of the fragments as possible to run with it. 



Now fill up the watch-crystal Avith water again, and stir 

 and pour off as before, and repeat the process until nearly 

 all of the male fluid has been washed out of the fragments 



