1/2 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 52 



each had only one (one or two, according to Risso^). In case of the 

 small species named Ceratobatis robertsii or massenoidea, the mother 

 likewise had a single foetus (a foetus sixteen inches wide). 



Although only one young is formed, that one is worthy of the 

 giant mother and larger than any of the full-grown common Rays of 

 ordinary size. It is practically immune from danger from the cus- 

 tomary enemies of fishes and well able to take care of itself. 



Nature is economical in her methods and there is some adjustment 

 of ways and means. In the case of egg-laying fishes of inferior size 

 and when no care is taken of the eggs, many thousands — even mil- 

 lions — may be laid by a single fish, and yet the number of adults 

 remains practically the same, generation after generation. In the 

 case of viviparous fishes like the Devil-fishes, a single young one at 

 a birth is enough to keep up the species. 



The fishermen of Jamaica, according to Hill, "say that the mother 

 fish makes the violent leaps she is seen to take out of the water to 

 eject the foetus from the matrix ; that the young fish is then observed 

 to fall from her ; and that for a time it swims upon the parent's back, 

 and possibly enters the wide mouth-sack when necessary to seek 

 shelter from apprehended danger." All this is improbable. It ap- 

 pears to be certain that the "leaps" are habitual to males and females 

 alike, and it is probable that they are the extension of their peculiar 

 mode of progression or "flight." 



A pregnant female, 15 feet wide and which with difficulty forty 

 men with two lines attached to it could drag along the ground, was 

 landed, after a five hours' fight, at Port Royal, Jamaica, in 1824. 

 "On opening it a young, about 20 pounds weight, was taken out, 

 perfectly formed" ; it was five feet broad. An account of the cap- 

 ture was given by Lieutenant Lamont in the Edinburgh Philosophi- 

 cal Journal (xi, T13-118). 



Two observations respecting the procreation of Devil-fishes re- 

 quire attention. 



That the Devil-fishes have only one young each, and consequently 

 are viviparous, is the statement made by all observers. This vivi- 

 parity is in analogy with the gestation in the relatives of the Devil- 

 fishes, all the Sting-rays and Eagle-rays. Nevertheless a gentleman 



* Risso, in his "Remarques" on the "Cephalopteres" gives the following data : 

 L'epoqne de leurs amours est I'hiver ; les femelles mettent has en Septembre un 

 a deux petits, qui originairement sont renfermes dans un oeuf oblong jaunatre. 

 Les males paraissent quelquefois n'abandonner leur compagne qu'apres qu'elle 

 a depose ses foetus; et si I'un des deux se jette dans un filet, I'autre ne tarde 

 jamais a le suivre. Risso Hist. Nat. Europe Mer., 3, 1826, p. 165. 



