436 



SCIENCE 



[N. S. Vol. XXIX. No. 741 



Though the sperms of crayfishes appear to be 

 killed by fresh water yet they are transferred by 

 the male to the outside of the female while under 

 water. A comparative study of the reflexes and 

 instincts involved shows the use of three sets of 

 organs in the male that are necessary for the 

 perpetuation of the species. These are the papillie 

 of the last thoracic limbs and the specialization 

 of the first and the second limbs of the abdomen. 

 In Camiarus there are also one or two pairs of 

 hooks upon the thoracic legs. 



The anatomy of these structures shows that in 

 Cambarus the first abdominal appendage is much 

 more complex and accurately adjusted than had 

 been thought, so that these crayfish are even more 

 highly evolved than they had been considered to 

 be. On the other hand, the like appendage of the 

 crayfish of Japan is not fundamentally as much 

 like that of Cambarus as had been thought, but 

 more primitive. This tends to lessen the difficul- 

 ties of one problem of geographical distribution 

 of crayfish by lessening the resemblance of eastern 

 Asiatic to eastern American forms. 



The evolution of the accurately interadjusted 

 male and female organs of sperm-transfer in cray- 

 fishes seems to admit of no present scientific ex- 

 planation. 

 Pelagic Nemerteans: W. K. Coe, Yale University. 



Comparative anatomical studies of numerous 

 species from various parts of the world leave little 

 doubt as to the affinities of these aberrant forms. 

 Eecent discoveries of pelagic species show that 

 they are distributed around the whole circumfer- 

 ence of the globe, and although they do not appear 

 to be abundant in any locality, the Arctic and 

 Antarctic oceans are the only large bodies of 

 water without known representatives. The struc- 

 ture of the proboscis, the arrangement of the 

 muscular layers of the body, and the disposition 

 of the blood vessels, indicate their origin from 

 more than a single one of the more generalized 

 types of Hoplonemerteans. 

 The Breeding Habits of the Squid: Gilmau A. 



Dbew, University of Maine. 



It has long been known that female squid with 

 nearly mature eggs have packages of sperm at- 

 tached to their outer buccal membrane. This 

 summer Professor E. G. Conklin observed a few 

 packages of sperm on the oviduct of a squid. 

 Observations following this have shown that this 

 is not an uncommon, but, on the other hand, not 

 a universal condition. 



The transfer of the sperm to both of these loca- 



tions has been observed many times during the 

 past summer. 



When the sperm is deposited on the oviduct, 

 the male grasps the female around the body just 

 behind the mantle opening, or frequently attaches 

 further back and crawls forward. The dorsal side 

 of the male is usually just below or a little to the 

 left of the ventral side of the female. The male 

 then extends its penis well into its funnel, ejects 

 a bunch of spermatophores, which it catches at 

 the outer opening of the f unn el with the end of 

 its left ventral arm. This arm, with the spermato- 

 phores, is immediately inserted far into the 

 mantle chamber of the female by the left side of 

 her neck above the funnel, and held there perhaps 

 ten seconds. Its position can sometimes be seen 

 through the transparent mantle of the female. It 

 is then withdrawn, the male releases the female, 

 and a few seconds later the empty cases of the 

 spermatophores escape from the female with the 

 water leaving her funnel. Examination of such a 

 female reveals fresh sperm sacs attached to the 

 oviduct. 



The transfer of sperm to the buccal membrane 

 is accomplished while the animals are attached 

 head to head. 



The discharge of the spermatophores is similar 

 to Rossia as described by Racovitza. 



Several females were observed while depositing 

 their eggs. Usually the female rests quietly upon 

 the bottom for several minutes before a string of 

 eggs is to be deposited. In this position she fre- 

 quently remains until the end of the string pro- 

 trudes about three quarters of an inch from the 

 funnel. She then begins to swim backward, 

 largely by means of the fin, but partly by water 

 that escapes from the funnel around the egg 

 string. While swimming in this manner, she 

 passes her two dorsal arms between the others 

 and catches the end of the egg string with them 

 and draws it up between the arms as it leaves 

 the funnel. Here it remains for two or three 

 minutes, entirely surrounded by the arms, which 

 are kept nervously moving against each other, 

 while she slowly swims about. Just before stick- 

 ing the egg string to the bottom, she becomes 

 exceedingly nervous in her actions and frequently 

 goes dancing over the bottom om the tips of her 

 arms with the body perpendicular, in a most sen- 

 sational manner. Suddenly, while the body is 

 perpendicular, or nearly so, she attaches to the 

 bottom with the ends of her arms, draws down 

 tight against the bottom and then withdraws, 

 leaving the egg string attached. 



