INDEX 



459 



Intercellular attachments, 52 



of muscle processes, 58 



see also Desmosome 

 Intercellular bridge, 81, 92 



between cnidoblasts, 45, 100 



functions of, 45, 79 



between germ cells, 48 



between interstitial cells, 45, 79, 92 



thickened membrane of, 79 



transfer of substances through, 79 



two types of, 80 

 Intercellular connections, 55 

 Intercellular septa, 56 

 Intercellular space, 55 

 Interstitial cell, 1, 10, 12, 45, 52, 54, 94, 



96, 135, 144, 421 



cnidoblast, differentiates into, 3, 78 



counts of, 410, 415 



differentiation of, 



chemical environment on, 341 

 factors on, 415 



in ectoderm, 2, 78 



in gastroderm, 78 



gonadal cell, differentiates into, 78 



gradient of, 415 



granular cytoplasm of, 88 



histology of, general, 2 



intercellular bridge of, 12, 45, 79, 92 



lipoic acid on, 416 



mesoglea, relation to, 419 



metabolic gradient, relation to, 426 



migration of, 417, 439 



mitosis of, 316 



mucous cell, differentiates into, 78 



nuclear pores of, 88, 90 



nutrition on, 415 



in regeneration, 404, 410, 415 



ribonucleoprotein granules of, 78 



syncytia of, 2 



X-rays on, 439 



zymogenic cell, differentiates into, 78 

 Intracellular digestion, 241 

 Intracellular vacuole, 55 

 Intrinsic factors, on regeneration, 401 

 Invaginated capsule, of stenotele, 132 

 Ions, inorganic, 



on Clilorohtjdm growth, 259, 266 



on development, 204 



on feeding reflex, 213-215 



on regeneration, 405 



see also specific ions 

 Isolation, 



of A. elegantissima cells, 245 



of nematocysts, 

 hydra, 154 



Isolation, 



of nematocysts, 

 Physalia, 171 

 Isorhiza, 104, 114, 189 



development of, 82 



holotrichous, 85 



structure of, 85 



a-Ketoglutaric acid, 361 

 Krebs cycle, relation to sexual differen- 

 tiation, 361 



Leeuwenhoek, 131, 441 



Light, on calcification, 271, 272, 279 



Limestone, 279 



Limnocnida, 326 



Lipid droplet, in cnidoblast, 82 



Lipofuscin, 440 



accumulates in aging tissues, 3'^9 



characteristics of, 379 



enzymes of, 379 



in human myocardiiun, 378 

 Lipoic acid, 418, 421 



on cell migration, 416 



on gastrodermis, 416 



inhibits malic dehydrogenase, 410 



on interstitial cells, 416 



on regeneration, 399, 408, 414 

 of Cliloiohydra, 414 

 of H. littoralis, 414 

 of planaria, 410 



reversed by oxaloacetate, 410 

 Lithothamnioid algae, in reef building, 270 

 Longevity, 



of BouganviUia, 311 



of Campamdaria, 311 



of Clytia. 312 



oi Cordylopliora, 311 

 Lumen, 4, 6, 18, 20, 24, 36, 59 

 Lysosome, 86. 246, 247, 250, 253, 378, 



379, 387 



acid phosphatase of, 381 



size of, 398 

 Lysozynic, action on mucus, 252 



Maeroenvironment, 343 



contrasted to microenvironment, 338 

 Rachevsky's formulation of, 340 



Magnesium, 



inhibits feeding reflex, 215 

 required for C. viridissima, 266 



Malic dehydrogenase, inhibited by, 

 cyclic-disulfides, 410 

 lipoic acid, 410 



