REPORT OF COMMISSIONERS OF INLAND FISHERIES. 117 



imd in either square or circular cars of cotton or linen scrim, of bobbi- 

 nct, of canvas, or of wood. Any constant motive power can be used 

 according to the exigencies of particular cases — steam, hot-air, or 

 gasoline engines; spring, weight, or water motors; or the water can be 

 stirred by hand with much labor, but good results as in our early 

 experience. Various forms of power transmission may also, of course, 

 be utilized; belt and rope drives over pulleys and sheaves, and steel 

 shafting with mitered gears, worms, etc., have all been successfully 

 utilized. 



HOW THE METHOD MEETS THE DIFFICULTIES. 



The way in which this very simple method overcomes the many 

 difficulties of confining larval lobsters may be described in general 

 terms as follows: In the first place the rearing cars are placed directly 

 in the sea, and thereby all the disturbing factors so difficult to control 

 in case of aquarium water which has been pumped and forced through 

 closed pipes, stored in tanks, aerated by air pumps, etc., are at once 

 avoided and, at the same time, the various known and the subtle 

 unknown requisites of healthy sea water are assured. The continuous 

 upward spiral current of the contained water is the panacea of 

 numerous troubles. By the upward trend of the current the larvae 

 are kept always afloat, which is their normal condition and the only 

 one to which they are, by structure and habit, adapted. The 

 strength of the current easily overpowers their own weak efforts at 

 swimming, sweeps them round and round, and effectually prevents 

 their congregating in common response to the stimuli of light. 



When the fry are prevented from getting to the bottom and from 

 congregating anywhere, several difficulties vanish. The effects of 

 cannibalism, which constitute perhaps the most serious difficulty of 

 all, are thereby greatly alleviated, for the fry are to a comparatively 

 great extent prevented from reaching one another, and, of course, the 

 disastrous effects of their becoming stranded on thfe sides or lying en- 

 tangled and fouled at the bottom are also obviated. Another most 



