In vitro fertilization in Bombyx Mori , the silkworm. Was John Hunter right or wrong in 1792?

Abstract

It seems suitable first to consider the normal mechanism of fertilization and egg-laying in the Lepidoptera (see figure 1). At mating, spermatozoa are intro­duced in one or more little sacs (spermatophores) into the copulatory opening (a) of the female; from there they proceed to the bursa copulatrix (b). After a few hours the membrane of the spermatophores dissolves, and the spermatozoa make their way (either by muscular contraction of the passages or by means of chemical stimuli) through the ductus seminalis (c) into the common oviduct (d) and thence by another fine duct into the receptaculum seminis (g). When a mated female is about to lay, a muscular contraction occurs which pushes each egg towards the ovipore (h); the eggs still in the abdomen of the females, above the single fertile one, remain waiting. During this time meiosis does not occur, the eggs remaining diploid. The stimulus for meiosis starts when the sperm enters the egg through the micropyle as, or just before, it is laid.