| Chapter III. The Distribution of Sexes | 5264 |
| Chapter XII. The Halicti: a Parasite | 5680 |
| Chapter VIII. Parasites | 5643 |
| Chapter IX. The Theory of Parasitism | 6529 |
| Chapter X. The Tribulations of The Mason Bee | 7289 |
| Chapter III. Another Prober (Perforator) | 6276 |
| Chapter XVI. A Parasite of The Maggot | 6696 |
