18 TWENTY-EIGHTH ANNUAL MEETING 



skimmings we have taken from the surface, but in the labora- 

 tory up to the present time they have not done very v^'ell with 

 that food. I think we have probably tried a hundred or more 

 different things, but the digestive gland of a full grown lob- 

 ster is made up of a number of little threads like fingers if 

 you look at it under a microscope; and if you take this diges- 

 tive gland and break it up into small pieces — we first shake it 

 in a glass till it is shaken apart — those little morsels are just 

 the right size for a little lobster's mouth; but the air that gets 

 in when you shake the digestive gland, or the liver, as it is 

 called, makes the pieces so light that they tend to float on the 

 surface and a young lobster will not take food from the sur- 

 face; he will not ordinarily take food from the bottom; it is 

 the food that is sinking down through the water, slowly, that 

 excites his appetite; but if this liver is put onto a board and 

 then a knife is taken and you cut it up into microscopic pieces 

 and are careful to rinse that ofE, fill a flask and allow it to 

 settle and pour off the supernatent fluid, and then wash again, 

 so that you are not throwing wholly organic matter into the 

 water you can take a little pipette full and squirt a little into 

 these jars that hold the young lobster, and in about an hour 

 you will notice a little yellow ball on the interior of each one, 

 that means that its little stomach is just as full of that lobster 

 liver as it will hold, and I assure you that those young lobsters 

 are immediately to be distinguished from those lobsters which 

 have been injured in the hatching process, or which, for some 

 reason or other do not eat, and will undoubtedly die. But by 

 far the larger number of lobsters will take the food, and the 

 color of the jar as it stands on the table is very different from 

 the color of the jar that contains young lobsters that have not 

 fed. There are probably two or three thousand in this jar. 



A Member: What is the form of this fourth condition that 

 you speak of? 



Mr. Bumpus: The fourth stage is very different from the 

 stage that immediately precedes it. You would not take them 

 for lobsters at all. The first three stages are more shrimp-like, 

 and they have external gills that make the interior of the body 

 look very fuzzy, or like chenille, as they move through the 

 water. The rapidity of growth and the molting depend upon 

 temperature and food. The experiments which we have made, 

 and which I did not allude to in my paper, convince me that 

 we have never given aquatic animals, marine animals, cer- 

 tainly, credit for growing one-half as rapidly as they will grow 

 under favorable conditions, and with an abundance of food. 

 There are many marine organisms that you can feed and notice 

 an increase in size on the following day. 



Mr. Titcomb: There is a red one here. Is that the color it 

 assumes when it is dying? 



