SPAWN OF CHITON AND OF THE CEPHALOPODA 



^7 



to elevate the posterior part of the girdle, and to pour out a 

 continuous stream of flaky white matter like a fleecy cloud, 

 which proved to be of a glutinous nature. It then discharged 

 ova, at the rate of one or two every second, for at least fifteen 

 minutes, making a total of 1300 to 1500, each being about -^-^ 

 inch diameter. The ova were shot into the glutinous cloud, 

 which seemed to serve as a sort of nidus to entangle the ova and 

 prevent them being carried away. The subsequent development 

 was rapid, and in seven days the young Chiton was hatched, 

 being then about 2V i^^ch long. Loven has described the same 

 species as laying its eggs, loosely united in clusters of seven to 

 sixteen, upon small stones. There is probably some mistake 

 about the identification, but the observation illustrates the vary- 

 ing methods of oviposition among allied forms. 



Not very much is known with regard to the ovipositing 

 of the Cephalopoda^ especially those which inhabit deep water. 

 Masses of ova arranged in very 

 various forms have occasionally 

 been met with floating in the 

 ocean, but it is next to impossi- 

 ble to determine to what species, 

 or even genus, they belong.^ 



In Loligo punctata the ova 

 are contained in small cylindri- 

 cal cases measuring 3 to 4 in. 

 by J in., to the number of about 

 250 ova in each case. Hun- 

 dreds of these cases are attached 

 together like a bundle of sau- 

 sages or young carrots, and the movements of the embryos within 

 can be distinctly noted. Sepia officinalis lays large black pear- 

 shaped capsules, each of which is tied to some place of attach- 

 ment by a kind of ribbon at the upper end of the capsule, 

 the whole forming a large group like a bunch of grapes. 

 Octopus vulgaris deposits thousands of small berry-shaped ova, 

 attached to a string which runs along the centre of the mass 

 (Fig. 43). 



The so-called shell of the female Argunauta is nothing more 



1 Examples will be found in Journ. Linn. Sac. Zool. xi. p. 90 ; Ann. Sc, 

 Nat. XX. p. 472 ; Zeit. wiss. Zool. xxiv. p. 419, 



Fig. 43. — Egg-capsules of A, Sepia elegans 

 Orb., and B, Octopus vulgaris Lam. 



