Science: Ice Packs for Fathers

In Portugall, along the river Tagus, & about Lisbon, certaine it is, that when the westwind blowes, the mares set up their tailes, and turne them full against it, and so conceive that genitall aire in steed of naturall seed: in such sort, as they become great withall, and quicken in their time, & bring forth foles as swift as the wind, but they live not above three yeres.

No less fantastic than this lore from Pliny’s Natural History* was the fertilization of rabbits reported before the sober American Philosophical Society last week. Not the wind but simply cold, applied by ice packs to the bellies of doe rabbits, made them pregnant, reported Physiologist Herbert Shapiro of Philadelphia’s Hahnemann Medical College.

Shapiro’s feat is the latest development in the artificial parthenogenesis, or sexless reproduction, of mammals. Sexless reproduction occurs naturally among many insects and has long been induced by curious biologists in sea urchins and frogs. Fatherless mammals were first produced in 1939 by Dr. Gregory Pincus (now of Clark University), who artificially fertilized ova from doe rabbits by 1) a salt solution, 2) heat, 3) cold. The salt-fertilized eggs, with no contact at all from the male, were replanted in the does and gestated normally into healthy bunnies, themselves capable of sexual reproduction.

Shapiro has now dispensed with Pincus’ careful surgery. He anesthetized female rabbits so they would lie still and not suffer; then he applied ice packs on their flanks directly over their Fallopian tubes. The rabbits’ temperatures, normally about 103.5° F., dropped to from 92.5° to 64.4° F., but they all recovered easily from the chill.† Afterward, at various intervals, Shapiro removed the cold-fertilized ova from the rabbits, found some of them well along toward embryonic development. If he learns why & how mere cold can fertilize a mammalian egg, Shapiro may thereby explain how the meeting of spermatozoan and ovum forms the beginning of another human life.

Shapiro has not yet allowed his pregnant virgins to give birth, chiefly because he is not interested in biological pranks but in study of cellular and embryonic development. A further reason: callous to the delicate distinctions and aims of science, newshawks might well sensationalize his discoveries, warn damsels to shun snowdrifts, wear woolies. And, like all parthenogeneticists, Shapiro must keep in mind the fate of pioneering Dr. Pincus, who was once quietly dropped from Harvard because his rabbit tinkering was judged to be in rather bad academic taste.

*As translated from the Latin in Philemon Holland’s famous version of 1601.

† Human beings have recovered from temperatures as low as 75° F., artificially induced as a form of cancer therapy (TIME, May 29, 1939).