xx xiv 



INDEX. 



with reference to the origin and 

 gradual appearance of sexual dif- 

 ferentiation. Table facing ii. 552 ; (4) 

 modes of development in relation 

 to sexual multiplication occurring 

 during its progress, ii. 567; (5) 

 causes which determine forms of 

 organisms, ii. 600; (6) communi- 

 cable diseases, cxlvi. 



Tardigrades, origin of, from Eugle- 

 n. v.' ii. 466 ; transformation of 

 Actinophrys into, ii. 524; repro- 

 duction in, ii. 532 ; Pangenesis in, 

 ii. 549 ; peculiarities of Pangenesis 

 in.'ii. 551. 



Theory, test of true, ii. 605- 



Thomson, Prof. Allen, on develop- 

 ment of ova in Ascarides, i. 200 ; 

 on individuality, ii. 556. 



Thomson, Sir William, on geological 

 time, ii. 619. 



Torulce, i. 273 ; mode of origin of, 

 in solutions, i. 281 ; nature of, ii. 

 141; development of, into Fungi, 

 " i45-<54; interchangeability of 

 Bacteria and, ii. 143 ; origin of, 

 within closed flasks (see Arcbebio- 

 *is, experiments relating to). 



Transformations, in Spirogyra, ii. 

 374, 387 ; in Moss-radicles, ii. 

 376 ; in Gonidial-cell, ii. 378; of 

 Trichomonas, ii. 384 ; in Vauche- 

 ria, ii. 394 ; in Nitella, ii. 399 ; of 

 Chlorophyll vesicles, ii. 415; of 

 Chlorophyll vesicles of Vaucheria, 

 Nitella, etc. into Desmids, ii. 418; 

 of cell-contents of Conferva into 

 Euglenae, ii. 421; of Spirogyra 

 into Astasiae, ii. 421 ; of Potamo- 

 geton into Euglence, ii. 422; M. 

 Kiitzing on, of vegetable organ- 

 isms, ii. 432; Reissek on, of Chlo- 

 rophyll vesicles and pollen-grains, 

 ii. 4*2 ; of Euglenae, ii. 436-466 ; 

 of Ciliated Infusoria, ii. 492-504 ; 

 of Actinophrys into Rotifers, ii. 

 504 ; of Vegetal vesicles into Ro- 

 tifers, ii. 506-521 ; of Rotifers 

 into Nematoids, ii. 522 ; of Acti- 

 nophrys into Nematoids and Tar- 



digrades, ii. 524; of Euglenge into 

 Rotifers, Tardigrades, and Nema- 

 toids, ii. 525; of resting-spore of 

 Vaucheria into Nematoids, ii. 528. 



Tre"cul, M., on development of Toru- 

 Ise, ii. 147; origin of Amylobacter, 

 ii. 318. 



Treviranus, experiments in reference 

 to heterogeny, i. 259. 



Trichoda, origin of, from Euglenge, 

 ii. 462 ; metamorphosis of Oxy- 

 trica into, ii. 496. 



Trichomonas, origin and transform- 

 ations of, ii. 384. 



Tubercle, non-specific nature of, 

 cxiii, cxvii ; generalization of, cxvi. 



Turpin, M., heterogenetic changes 

 in milk-globules, ii. 311; mode of 

 origin of Uredo, ii. 339. 



Types, persistence of, ii. 606; per- 

 sistent, Prof. Huxley on, ii. 615; 

 explanation of persistent, ii. 616- 

 619; dominant, ii. 621. 623; of 

 fish and insect, ii. 624 ; estimation 

 of worth of, ii. 625 ; vertebrate, ii. 

 626 ; elaboration of, ii. 627. 



Units, physiological, ii. 23, 90, 98, 

 ii. 603. 



Variation, ' spontaneous,' meaning 

 of, iii 595 ; instances of, ii. 596- 



599- 



Varicella, cxliii. 

 Vaucheria, formation of spore of, i. 



173; transformations in, ii. 394.; 



of spore of, into Nematoids, ii. 



528. 

 Vegetable forms, interchangeability 



of animal and, ii. 431, 434. 

 Vibriones, nature of, i. 274; vital 



resistance of, to heat, i. 317. 

 Virchow, Prof., doctrines concern- 

 ing, i. 148 : cellular pathology, i. 



158 ; activities of tissue-elements, 



.i. 167. 

 Vital forces, correlation of physical 



and, i. 16-49, 60; dependent on 



