. The physiology of the Invertebrata. Fig. 70.—The Eye of the Decapoda. A = Eye of Astacus. B = Eye of Homarus. a = cornea, b = crystallinecones. c = nerve rods. d = striated bodies. e = optic lenticular bodies, g-= fenestrated membrane. A = layer not presentin Astacus. k = pigment cells between cones. C = cornea of Decaf = cornea of Insecia. There are certain species of crayfishes which are blind;among these may be mentioned Gambarus setosus (Faxon),which lives in the caves of south-western Missouri, andCamhartis pellucidics, the well-known species from the Mam-moth Cave. Mr. G
. The physiology of the Invertebrata. Fig. 70.—The Eye of the Decapoda. A = Eye of Astacus. B = Eye of Homarus. a = cornea, b = crystallinecones. c = nerve rods. d = striated bodies. e = optic lenticular bodies, g-= fenestrated membrane. A = layer not presentin Astacus. k = pigment cells between cones. C = cornea of Decaf = cornea of Insecia. There are certain species of crayfishes which are blind;among these may be mentioned Gambarus setosus (Faxon),which lives in the caves of south-western Missouri, andCamhartis pellucidics, the well-known species from the Mam-moth Cave. Mr. G. H. Parker* has recently examined thequestion of degeneration of these organs. He states that * Bulletin of the Museum of Comparative Anatomy at Harvard College,vol. 20 (1890). PHYSIOLOGY OF THE INVERTEBRATA. 365 not only has the finer structure of the retina been affected,but the shape of the optic stalks has been altered. Theoptic stalks are not only proportionally smaller than those ofcrayfishes possessing functional eyes, but
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectinverte, bookyear1892
