594 SCIENTIFIC EECORD FOR 1882. 



jacGDt to the mantle, and between the latter and the liver, disappears, 

 together with all traces of the reproductive organs, ducts and all. " At 

 the first bend of the intestine there is still some of the connective tissue 

 remaining, but even here and in the mantle it has changed its charac- 

 ter entirely, and become very spongy and areolar, instead of solid, and 

 composed of .large vesicular cells, such as are met with when the animal 

 is in a better condition of flesh. In fact, it appears as if this mesen- 

 chymal or connective tissue substance had been used up and converted 

 into reproductive bodies — generative products — in the case of the 

 spawn-spent and extremely emaciated individuals. In sections from 

 individuals in various conditions, from that in which the rudimentary 

 network of generative tubules has just appeared in the connective 

 tissue, on up to those in which the reproductive tissues are enormously 

 developed in bulk and proj^ortion to the mass of the remaining struct- 

 ures, there is a perfect gradation from their complete absence to their 

 full development. This would api^ear to be very strong evidence in 

 support of the theory that the reproductive follicles or tubules are de- 

 veloped anew each season directly from the specialization of certain 

 strings or strands of connective tissue cells." 



Mr. Ryder adds that many animals manifest a j)eriodic development 

 of the glandular portions of the reproductive organs, but he knew of no 

 form in which there is any such presumptive evidence that these organs 

 are annually regenerated and finally altogether aborted as seems to be 

 the case with the oyster. "Together with the changes here described, 

 the most remarkable changes in the solidity and consistence of the ani- 

 mal take place. The shrinkage of a spawn-spent oyster in alcohol or a 

 chromic acid solution is excessive, and will, when complete, reduce the 

 animal to one-tenth of its bulk while alive. This shrinkage is due to 

 abstraction of the water with which the loose, spongy tissue of the ex- 

 hausted animal is distended. A so-called 'fat' oyster, on the other 

 hand, will suffer no such excessive diminution in bulk when placed in 

 alcohol or other hardening fluid. In consequence of this variable de- 

 velopment of the reproductive organs as well as that of the connective 

 tissue of the body mass, the amount of solid protoplasmic material con- 

 tained in the same animal at different times must vary between wide 

 limits. And inasmuch as the nutritive and reproductive functions of 

 animals are notoriously interdependent, it follows in consequence of 

 the enormous fertility of the oyster that a vast amount of stored mate- 

 rial in the shape of connective tissue must be annually converted into 

 germs and annually replaced by nutritive processes. Plenitude or 

 dearth of food are also to be considered, but it now becomes a little 

 easier to understand the physiological interdependence of the repro- 

 ductive function and the so-called fattening process. 



"The widespread belief in 'fat' and 'poor^ oysters is simply a 

 widespread delusion, if it be maintained that fleshy oysters owe their 

 rotundity to a deposit of oleaginous or fatty matter. Far from deny- 



