446 EXPLANATION OF FIGURES. 



FIG. 9. Lateral views of skulls of three kittens from same litter (F = ). The animals were all sacrificed on the twenty- 

 seventh day after the experimental procedure. The skull to the light is that of the control to which no 

 injections were given. On the left is the skull of the kitten which received an intraventricular injection of 

 1.0 c.c. of a 5 per cent suspension of cinnabar. No change from the normal was noted in this kitten during 

 life; at autopsy the skull was complete!}' closed by bony union, as was the control's. In the center is the 

 skull of the third kitten which received when 4 days old 1.0 c.c. of a 5 per cent suspension of lampblack. 

 Typical internal hydrocephalus resulted. 



FIG. 10. Photograph of sectioned heads of same kittens as shown in figure 9. The skull-cap and underlying brain 

 have been removed in same way from each. On the right is the control kitten; on the left is that of the kitten 

 receiving intraventricular cinnabar. In the center is the hydrocephalic kitten which was given the intra- 

 ventricular injection of lampblack. 



FIG. 11. Photograph during life of a kitten which received a aubarachnoid injection of 1.0 c.c. of a 10 per cent suspen- 

 sion of lampblack, when 20 days old and when skull was closed. Photograph was taken on twelfth day after 

 the injection. Full protocol of animal in text. 



FIG. 12. Lateral views of skulls of two kittens from same litter (N 3 ). Above is the skull of the control animal while 

 below is that of the same kitten as in figure 11. After receiving subarachnoid injection of lampblack, 

 kitten lived 15 days; control was killed on same. day. 



FIG. 13. Photograph of skulls of same kittens as given in figure 12. The control appears to the right, hydrocephalic 

 on the left. 



FIG. 14. Photograph of sectioned heads of same kittens as recorded in figure 12. On the right is the control; on the 

 left is the head of the kitten receiving subarachnoid injection of lampblack (cf. fig. 11). 



FIG. 15. Lateral view of skulls of two kittens from same litter (Os). On the right is the control; on the left is the 

 skull of kitten receiving subarachnoid injection of 1.0 c.c. of a 10 per cent suspension of lampblack. At 

 time of injection this kitten was 10 days old. Animal developed a typical hydrocephalus and was sacri- 

 ficed with control on the twenty-second day after injection. 



FIG. 16. Photograph of sectioned heads of same kittens as in figure IS; on the right is the control, on the left is the 

 hydrocephalic. The carbon granules occurring on the ventricular floor are typical of the deposit which occurs 

 after such subarachnoid injection. 



FIG. 17. Photograph from above of skulls of two kittens from same litter (.!;). On the right is that of the control 

 animal, on the left is that of the experimental animal. This kitten when 42 days old was given a subarach- 

 noid injection 1.0 c.c. of 5 per cent of lampblack in normal saline. The skull which was previously tightly 

 closed opened up and wide suture lines were formed. Sacrificed, with control, on twenty-first day after 

 injection. 



FIG. 18. Lateral view of same skulls as reproduced in figure 17. The control is below, the experimental hydrocephalic 

 above. 



FIG. 19. Photograph of transversely sectioned skulls of same kittens as in figures 17 and 18; photograph taken from 

 behind, looking toward nose. On the right is the control; on the left the experimental animal, showing 

 resulting internal hydrocephalus. 



FIG. 20. Photograph of sectioned heads as in figure 19, taken looking toward the occiput. The enlargement of tem- 

 poral cornua of lateral ventricles is shown. 



