47 



9 Head of Male Mosquito. 



10 Leg of Blow Fly. 



1 1 Eye of Horse Fly. 



12 Portion of Wing of House Fly. 



13 Scales from Wing of Moth. 



14 Wool Fibres. 



15 Section of Wheat Straw. 



16 Heliopeltea. 



17 Fine Muslin showing Cotton 



Fibre. 



18 Foot of Fly showing Structure 



of Pads. 



19 Proboscis of Fly Anthromya 



Lardaria. 



20 Saws of Saw Fly. 



Additional Photographs of Microscopic 

 Objects enlarged from Nature. 



PER SLIDE, $2.00. 



21 The Human Louse. 



22 The Crab Louse. 



23 The Bedbug. 



24 The Flea. 



25 The Fly. 



26 Marine Algae. 



27 Hunting Spider. 



28 Parasite of Chicken. 



29 The Common Mosquito. 



30 Eye of Fly. 



31 Sting of Bee. 



32 Human Itch Insect. 



33 Tongue of a Hornet. 



34 Tongue of a Bee. 



35 Parasite from a Fig. 



36 Parasite from a Sparrow. 



37 Scale from the Wing of a Butter- 



fly. 



38 Parasite of a Beetle. 



39 Parasite of a Chaffinch. 



40 Parasite of a Field Mouse. 



41 Parasite of a Swallow. 



42 Parasite of a Mole. 



43 Flea of a Mole. 



44 Flea of a Mole Pigeon. 



45 Eye of a Beetle. 



46 Gizzard of a Cricket. 



47 Water Beetle. 



48 Leaf Insect. 



49 Scale from the Wing of a Moth. 



50 Saw of the Saw Fly. 



51 Spiracle of a Cockchafer. 



52 Tongue of a Drone Fly. 



53 Trachea of a Silk Worm. 



54 Tongue of a Hornet. 



55 Transverse Section of Bono. 



56 Scale of a Fish. 



57 Human Blood Corpuscles 



58 Section of a Tooth. 



Class XXXV Crystallography, 



Arranged as in Rosoe'a Chemistry. 

 TEN SLIDES, PER SET, $15.00. 



1 The Primary Forms of the Six 



Systems. 



2 Secondary Forms of the First or 



Regular System. 



3 Secondary Forms of the Second 



or Quadratic System. 



4 Secondary Forms of the Third or 



Hexagonal System. 



5 Secondary Forms of the Fourth 



or Rhombic System. 



6 Secondary Forms of the Fifth or 



Monoclinic System. 



7 Secondary Forms of the Sixth or 



Triclinic System. 



8 Ice Flowers (Tyndall). 



9 Snow Crystals. 

 10 Ice Crystals. 



Class XXXVI Spectrum Analysis. 



TWENTY SLIDES, EACH, $2.75. 



1 Decomposition of Light by Prisin 



(Solar Spectrum). 



2 Comparative Intensity of Heat- 



ing Luminous and Chemically 

 Active Rays in Spectrum. 



3 Fraunhofer's Map of Solar Spec- 



trum. (1814-15.) 



4 The Spectroscope. 



5 Spectra of the Sun, Beta Cygni, 



and Hydrogen. 



