Cytology of Polyphagus Euglenae . 
199 
DESCRIPTION OF FIGURES IN PLATES XVI-XIX. 
Illustrating Mr. Harold Wager’s paper on Polyphagus. 
(Except where otherwise stated the figures have been drawn with the aid of a camera lucida, 
using the apoc. obj. 2 mm. of Zeiss and compensating oc. 8.) 
PLATE XVI. 
Fig. 1. Copulation of male and female cells. Copulating tube very long. The young zygote 
is just beginning to form as a swelling at the apex of the copulating tube in contact with the female 
cell. (Obj. Zeiss D, oc. 8, Cam. lucida sketch.) 
Fig. 2. Male nucleus just ready to pass along the copulating tube into the young zygote. The 
copulating tube shows three slight swellings along it. 
Fig. 3. Zygote at a slightly later stage than in Fig. 1. Copulating tube larger in diameter and 
shorter. (Obj. Zeiss D, oc. 8, Cam. luc. sketch.) 
Fig. 4. Young zygote, showing male and female nuclei just about to pass into it. Copulating 
tube short. (Obj. 2 mm. apoc., oc. 8, freehand sketch.)) 
Fig. 5. Young zygote, showing male nucleus inside and female nucleus ready to pass in. 
(Obj. Zeiss D, oc. 8, freehand sketch.) 
Figs. 6-21. Germination of zygote. (Obj. Zeiss D, oc. 4, freehand sketches.) 
Fig. 6. Zygote just beginning to germinate in November. 
Fig. 7. Shows contents of zygote with fatty granules. 
Fig. 8. Ditto, later stage. 
Fig. 9. Oily masses beginning to break up. 
Fig. 10. Oily masses breaking up into minute granules which appear black under microscope. 
Fig. 11. Vacuoles appear; further breaking up of fat granules. 
Fig. 12. Fat completely broken up into minute granules arranged in strings. 
Fig. 13. Minute fat granules surrounding vacuoles. 
Fig. 14. Ditto, more regular arrangement of vacuoles. 
Fig. 15. Fat globules fusing together. 
Fig. 16. Later stage of fusion. 
Fig. 17. Granules, much fewer, nearly all same size, one for each zoospore. 
Fig. 18. Contents divided into polygonal masses, the young spores. 
Fig. 19. The spores completely separated. 
Fig. 20. The spores, just before they escape, become slightly elongated. 
Fig. 21. Spores escaping; the three shown were unable to get out for some time. 
Figs. 22-25. Successive stages in the segregation of spores in a portion of an asexual sporan- 
gium. (Obj. Zeiss D, oc. 4, freehand sketches.) 
PLATE XVII. 
Fig. 26. Sporangium just beginning to form on the vegetative cell. 
Fig. 27. Young sporangium just formed on the vegetative cell with nucleus just passing into it, 
surrounded by a deeply stainable chromidial mass with oil globules. The large nucleolar mass of 
chromatin has become constricted, in its passage through the opening, into a large anterior and 
a small posterior portion, with a drawing-out thread between them. 
Fig. 28. Sporangium just being formed. The membrane around it is visible and is seen to be 
continuous with that of the male cell. The nucleus has just passed into the sporangium, and in the 
passage a small portion of it has been left behind. A number of chromidial granules are scattered in 
the protoplasm which is passing into the sporangium. The rest of the chromatin mass (nucleolus) 
