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oviducts unite in a thick-availed , triangular sac whose posterior angle 

 is continued into the ovipositor. 



I have found eggs in the middle and last portions of the oviduct, 

 but much more abundantly in the last. Their number varies greatly ; 

 in one specimen, for example, there were three eggs in each oviduct; 

 in a second there were seven in one and six in the other; in a third 

 there were eight in one and nine in the other. 



The eggs at the time of laying shew no appearance of embryos 

 within them. They consist of a quantity of milky fluid, containing 

 very many yolk granules, enclosed in a very thick, tough, but rather 

 soft envelope of a pale yellow colour and beautifully sculptured on the 

 outside. The sculpturing consists of little crumpled papillae, some- 

 what resembling worm-casts, arranged at fairly regular intervals over 

 the surface, and with much finer, meandering ridges occupying the 

 spaces between them. The eggs are oval in shape and measure about 

 1-9 by 1-5 mm. 



A careful re-investigation of my material has led me to the follow- 

 ing conclusions with regard to the egg-envelope. The envelope really 

 consists of three membranes. 1) A very thin, transparent membrane 

 immediately surrounding the yolk and probably to be regarded as a 

 vitelline membrane. 2) A very thick membrane which is apparently 

 formed as a secretion in the thick-walled part of the oviduct. In sec- 

 tions of a female containing eggs in the oviduct this membrane is very 

 conspicuous and is seen to have a thickness of about 0-036 mm. It is 

 of a pale yellow colour and has a very finely granular appearance. In 

 a former paper I erroneously stated that the egg-membrane is smooth 

 or nearly so w^hile still in utero. It is true that the complete sculp- 

 ture is not formed till the time of laying, but my recent observations 

 have shewn conclusively that the foundations of that sculpture are al- 

 ready present when the eggs are lying in the last portion of the ovi- 

 duct. These foundations consist of a number of little rounded protu- 

 berances regularly distributed over the surface of the thick membrane 

 and each having a diameter of about 04 mm. They are not very ob- 

 vious in fresh specimens and require careful looking for, but in speci- 

 mens which have lain for a long time in alcohol previous to dissection 

 the thick egg-membrane assumes a rather dark brown colour and the 

 protuberances are conspicuous in surface view as much darker, well- 

 defined circular areas. 3) The fortunate discovery of an egg partially 

 extruded from the greatly distended ovipositor in a specimen preserved 

 in alcohol indicates the formation of a thin, transparent membrane 

 outside the thick one just described. This membrane appears to be 

 formed as a secretion, probably by the walls of the triangular sac at 



