OVSTI'.K BOTTOMS IN MATAGORDA BAY. 81 



the volume of the head of an ordinary pin. The method of extract 

 ing the food from the stomach is admittedly crude and inexact, and 

 undoubtedly a considerable proportion of the stomach contents are 

 not withdrawn, but even so the results show thai the volume of food 

 at an\ given time must be very much smaller than ha- heretofore 

 been suspected. Basing the opinion upon the known rate of growth 

 Of oysters, and under the extreme assumption that the food in con- 

 certed into oyster bulk for bulk, the rate ol ingestion musl be vastly 

 more rapid than assumed by Grave or suspected by other investiga- 

 tors. An oyster whose body is 2\ inches long will, when in g I 



eondition, have a hulk of L2,000 to 15,000 •■.mm. Assuming that the 

 normal stomach content is one-fourth cubic millimeter, twice that in- 

 dicated above, and adopting Grave's statement that this normal con- 

 tent is ingested in four hours, it would require from 800 to l.oon days' 

 constant feeding for the oyster to procure food in bulk equaling its 

 own. We know that oysters on the gulf coast will grow to the 

 volume mentioned in less than two years, sustaining the while all of 

 the energy expenditures of metabolism and mechanical movement. 

 The matter merits investigation and the revision of the assumptions 

 of previous investigators, and the writer contemplate- it< considera- 

 tion in the near future. 



si' \WMX<; of OYSTERS. 



The spawning of oysters consists, in brief, of the discharge of eggs 

 from the female and spermatozoa from the male to meet ami fuse 

 in the surrounding water. The fertilized eggs develop into minute 

 embryos, each furnished with a little brush of cilia or hair-like proc 

 esses which vibrate in rhythm and propel it feebly through the water. 

 After a time varying with the temperature of the water the embryos 

 develop a tiny shell, which by it> weight eventually precipitates 

 them to the bottom, where, if they fall upon a suitable clean, firm 

 support, they attach and grow into spat, but i I' not they speedily 

 die. A.S their own powers of locomotion are inconsiderable, the wide 

 distribution of the young oysters in their swimming stage is depend- 

 ent upon the currents. 



Oysters in the spawning condition are of a peculiar creamy color, 

 with branching lines traced over the surfaces of the body. When 

 fchey are cut the ripe genital product- at once exude from the wound. 

 but if the -hell he opened carefully and a gentle pressure exerted 

 upon the body they will be discharged from a definite opening lying 

 helow the muscle (usually called by oystermen the ••eye" or 

 "heart") which extends between the two valve-. This is the pore 

 from which they flow in the normal process. Ripe oysters in the 

 Language of the oystermen are aptly described a- " milky." 



