226 BULLETIN OF THE BUREAU OF FISHERIES. 
unnatural and vicious cannibalism which Professor Morgan might well have 
added to his enumeration of characteristics impossible of development through 
natural selection and the survival of the fittest, for it can hardly be exercised 
at all under natural conditions. But whether this evil instinct arises from one 
or another biological antecedent cause or is a special inspiration in each particu- 
lar case, its reality is a constant and serious menace to lobster-culture operations. 
The cannibalistic tendencies are manifested as soon as the fry are hatched and 
continue throughout the larval period and, for that matter, even far beyond it. 
Not only do the larger and stronger specimens devour the weaker, but individ- 
uals of equal strength attack one another, and, apparently, some initial advan- 
tage determines the outcome. During the moulting period the mortality from 
these sources is naturally aggravated, because it is easy to tear to pieces the 
soft-skinned, freshly moulted individuals, while they, on their part, are unable 
‘to fend off attacks. 
Swimming habits—The comparatively aimless and weak swimming habit 
which characterizes the larve of the first three stages would seem, even in 
nature, to afford no protection, but for cultural operations, where large numbers 
of larve are given the restricted liberty of a small arm of the sea or are more 
closely confined in cars of any sort, it contributes to one of the most exaspera- 
ting difficulties. For example, it happened that when the fry in one of the 
early experiments of this series were placed in a small cove or inlet from the 
sea, especially prepared and apparently well adapted to their requirements, 
they were carried out by the first ebbing tide, and when, subsequently, a screen 
was stretched across the gateway they were carried against it and left stranded 
high and dry. In the many attempts to confine them in various forms of cars, 
when the current was allowed to pass through to prevent stagnation, a like 
result followed—the unresisting fry were always finally borne against the sides 
or bottom. 
Once upon the bottom the larval lobsters are utterly helpless; they lie 
upon their sides or backs beating the water with their exopodite “fins” and 
“kicking” with the whole body. They can not crawl; their only salvation 
is to “‘kick’’ themselves loose from entanglement and once more rise in the water. 
When confined in considerable numbers, even in still water, they inevitably 
find their way to the bottom as a consequence of their aimless drifting mode of 
swimming. ‘There they accumulate in corners, pockets, or eddies, and, entangled 
in débris, they fight and eat one another until, from injury or suffocation, they 
all perish. For the full appreciation of these difficulties there must be, how- 
ever, the personal recollection of particular rearing bags in which from day to 
day the precious living larve vanished from sight, and of the quarts of bright 
pink colored dead specimens mixed with dirt and silt and remnants of unused 
food that came into view when the bag was raised for inspection. In one of the 
