STUDIES ON VARIATION IN THE MEALWORM, 

 TENEBRIO MOLITOR. 



By S. a. ARENDSEN HEIN. 



I BIOLOGICAL AND GENETICAL NOTES ON 

 TENEBRIO MOLITOR. 



(With 16 Text-figures and 1 Diagram.) 



CONTENTS. 



FAOE 



A. The larva 228 



1. Colour 228 



2. Anomalies 229 



a. Eudimentary wings 229 



h. Segmental anomalies 230 



c. Variation of the spines . 232 



3. Duration of the larval period 234 



4. Number of Moults . . . 235 



B. The Pupa 235 



1. Dififerences of sex 235 



2. The ratio of the sexes 237 



3. Difference in length between the sexes 238 



C. The Beetle 241 



1. Secondary sex characters 241 



2. Duration and quantity of egg-production .... 243 



3. Duration of life of the sexes 244 



4. The copulation 245 



5. Sterile Eggs 248 



6. Coloration (Development of the adult coloration) . . . 249 



7. Hereditary and non-hereditary anomalies .... 252 



a. The eyes 253 



h. The antennae 254 



c. The prothorax 254 



d. The transverse rib 256 



e. Grooves and dints ........ 256 



/. Scutellum 256 



g. The elytra 257 



h. The legs 258 



D. Summary 262 



Journ. of Gen. x 16 



