Harris, Joseph P.

English

Southern Methodist University

124 FIELD AND LABORATORY [Vol. 20 appeared to be ineffective instinctive patterning for dealing with the situation; on the other hand, there was a marked desire for relief and protective aid. During the delivery crisis there was complete disintegration of organized behavior. The result was a return to the infantile pattern, made possible by the presence of a female parent who was still nursing a later offspring. From this case it appears that a highly intelligent cat, lacking adequate instinctive [or endocrinal ?] structuring and training, can in a crisis revert to infantile behavior as a method of restoring psychological equilibrium. Such an adjustment would be similar to the psychotic regression exhibited by some human beings under extreme conditions of frustration. Future partus-behavior of the subject will be observed and recorded. If such behavior as described above is a second time observed, it would be well to attempt (by endocrinal experiments or at least by autopsy) to ascer-tain whether some gonadic rather than a purely psycho-logical explanation is the more adequate. Note A CASE OF MONOZYGOTIC TWINNING IN THE SPINY DOGFISH, Squalus acanthias.--In a gravid female shark obtained off the coast of Maine in 1950, there was found a pair of "pups" attached to the same yolk sac. The specimen was preserved. Both pups are female, and each is about 125 mm. long. Each has a yolk stalk attaching to a common yolk sac, as in the figure. There is no external sign of separation of the yolk sac into two parts. One of the pups appears slightly thicker-bodied than the other; but this may be due to the intra-uterine position and space they occupied in the mother, when first preserved. Superficially the pattern of spots on the dorsum appears identical in the two specimens.--Joseph P. Harris, Jr. 

A Case of Monozygotic Twinning in the Spiny Dogfish, Squalus acanchias

https://scholar.smu.edu/cgi/viewcontent.cgi?article=1303&context=fieldandlab

A Case of Monozygotic Twinning in the Spiny Dogfish, Squalus acanchias

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Southern Methodist University