Published online by Cambridge University Press: 06 April 2009
1. A description is given of the egg of Gasterophilus intestinalis.
2. The chorion has been shown to consist of a number of tanned protein and lipoprotein layers.
3. The waterproofing of the egg is shown to be dependent on a primary wax layer on the inner membrane of the endochorion and a secondary layer on the vitelline membrane.
4. The respiratory requirements of the egg are supplied from a free-air space between the inner membrane and the tanned protein layer of the endochorion which communicates with the atmosphere by specialized pore canals opening into the follicular grooves.
Thanks are due to Dr P. Tate for suggesting the subject of this work and for his advice and encouragement during its progress.