| The authors of this volume have been resolute in their reference of the pathogeny of tic to a mental process. |
| One could not desire a more lucid exposition of the pathogeny of so many of these head-tossing tics. |
| A vicious circle in pathogeny is formed and the patient is likely to get into a very debilitated and depressed condition. |
| But no sufficient ground for such a pathogeny can be ascertained. |
