TABLE OF CONTENTS. 



III. Materials employed in the arts and manufactures — Continued. 



8. Pearl 151 



9. Shell 153 



Cameo sliell 153 



Shells used for implements 153 



10. Other materials from invertebrates 154 



11. Leathers 154 



Prepared from reptile-skins 154 



Prepared from fish-skins 154 



12. Isinglass 154,238 



13. Gelatines " 156,239 



14. Sponges 156 



Specimens of American commercial sponges 156 



15. Oils and fats 157 



Mammal-oils 157 



Reptile-oils , 160 



Fish-oils 160 



Mollnsk-oils : 162 



16. Perfumes 162 



Mammal-perfumes 162 



17. Chemical products and agents employed in the arts and medicine 162 



Derived from plants 162 



18. Fertilizers' 162,239 



Artificial guanos 162, 239 



Section F.— EESEARCH, PROTECTION, AND CULTURE. 



I. Investigation (as prosecuted by the United States Fish Commission) . 163 



1. Methods of work 163 



2. Results of work 164 



a. Puhlicatious 164 



b. CoUections 210 



c. Active work in fish-ciilture 210 



II. Protection 212 



1. Game laws. (See reports) 2 2 



2. Fish-ways 212 



Groove fish-ways 212 



Box, step, or pool fish-ways 212 



Inclined fish-ways without steps 213 



Spiral fish-ways 213 



Moving float fish-ways 213 



in. Propagation 214,239 



5. In general 214 



Devices used in obtaining and impregnating ova 214 



Hatching-houses .• 214 



Hatching-troughs and boxes, stationary 215 



Hatching-boxes, floating ^ ,. 217 



Adhesive-egg apparatus 217 



Floating hatching-houses 217 



Accessories to the hatching apparatus 217 



Devices for the transportation of fi, h-eggs 218 



Apparatus used in the transportation of fish 218, 239 



Appa ratus used in feeding fry 218 



