| Chapter III. The Distribution of Sexes | 5223 |
| Chapter XII. The Halicti: a Parasite | 5580 |
| Chapter VIII. Parasites | 5573 |
| Chapter IX. The Theory of Parasitism | 6462 |
| Chapter X. The Tribulations of The Mason Bee | 7259 |
| Chapter III. Another Prober (Perforator) | 6196 |
| Chapter XVI. A Parasite of The Maggot | 6637 |
