832 WINTERTON C. CURTIS 
2 ce. of oil of male fern, followed twenty-four hours later by about 
1 ce. (measured dry) of calomel. The dates and other points 
of importance are shown in the several columns, under appropri- 
ate headings. For convenience of reference, each shark is given 
a number. The column which shows the ‘condition at death’ is 
inserted because specimens did not always survive the treatment 
and thus some of those examined had died from its effects. Such 
specimens are marked ‘dead’ while others which were killed 
because they seemed about to die are marked ‘dying.’ The 
specimens which are marked ‘killed’ are those which appeared 
to be in perfect condition’ when they were taken and killed for 
examination. The specimens found soon after death (‘dead’) 
and those which were killed when they seemed likely to die 
(‘dying’), presented data of some value, for the reason that under 
normal conditions the death of the shark is not followed at once 
by the death and consequent disintegration of the parasites. 
One finds that living cestodes can be obtained from untreated 
sharks, which have been dead in the water, or lying exposed to 
the air upon the wharf for five or six hours and I have often seen, 
in my work with the students at the Marine Biological Labora- 
tory, spiral valves left exposed to the air all day yielding an 
abundance of C. laciniatum which were still alive and seemingly 
about as active as if taken from a shark just killed, and these 
worms if put into sea water may live for as long a period as forty- 
eight hours. In no case of an untreated shark which, on being 
injured by rough handling in my cars or by the collectors when 
first captured, was killed before it died from the effects of this 
handling did I find the approach of death in the host killing the 
parasites. We may therefore conclude that when, in a shark 
which has died very recently, or in one which has been killed 
because death seems approaching, there are found dead Cestodes, 
the worms have been killed by the drugs and not by the actual, 
or approaching, death of the host. Such cases have for this 
reason a sufficient value to be considered in the series. The 
objections against them are, first, that they do not represent indi- 
viduals taken at random, and second, that it is of no value to 
show that the worms are killed in the sharks which do not sur- 
