682 



INVEETEBEATA 



Metatroch of larva of JJreissensia, 340 ; of 

 larva of Phascolosoma, 376 ; of Actino- 

 trocha larva of PAorom's, 381 ; of larva of 

 Polygonlivs, 140, 144 ; of adult Polyzoa 

 Ectoprocta, 386 



Metazoa, 51, 100, 170 ; ancestry of. 116, 660 



Metazoaea larva, 213 



Method of finding eggs of ItoUchoglossus 

 kowalevskii, 582 



Methods of reconstructing sections, 319 



Met rid in a i marfiiiuit ii in, 85 



Micromeres in segmenting egg of -1//^A /".>//* 

 lanceolatus, 588 ; in segmenting egg of 

 JBeroe, 90 ; in segmenting egg of Dentalivm, 

 327, 328 ; in segmenting egg of Dreissensia, 

 333, 334; in segmenting egg of Erliini'x 

 esculentus, 506 ; in segmenting egg of 

 Patella, 293-295 ; in segmenting egg of 

 Phascolosoma, 373, 374 ; in segmenting 

 egg of Planocera, 104 



Mid-gut, formation of, in Agelenu, 230 ; in 

 Astu.cus, 189 ; in Donacia, 254 ; uiJvlus, 

 284 ; in Loligo, 358; in Scolopendro, 284; 

 metamorphosis of, in larva of GaleruceUa 

 ulmi, 269 



Middle piece of Spermatozoon, definition of. 7 



Miguel's solution, 131 



Millipedes, 281 



Mites, 242 



Mitrocrima, experiments on eggs of, 96 



Molgula, 628 



Moli/ulii ii,iii>nU<ii<les, development of, 632 



Mollusca, 105, 108, 157, 372, 400, 401, 405, 

 406, 408, 413, 416, 427, 435, 436, 457, 

 523, 529, 561, 562, 651, 655, 659, 661 ; 

 development of, 291-371 ; development of 

 unfertilized eggs, 17 ; eggs of, 9 : fossil 

 representatives of, 20 ; sperm of, used to 

 cross-fertilize eggs of Sea-urchin, 17 



Molluscan cross, definition of, 133 ; in seg- 

 menting egg of <_'irj'(hila, 322 ; in seg- 

 menting egg of r<ilrll, 294 : in srgmtnt- 

 ing egg of Phascolosoma, 374 ; in segment- 

 ing egg of Pobjijordhis, 133 



Molluscoida, 60S' 



Monotrochal larva, definition of, 153 



Monotus, 115 



Monovalens race of Ascaris megaloceplinln 

 439 



Morula of Tubular ia, 54, 55 



Mouth, formation of, in A/iiphio.cim lanceo- 

 lii.tits, 596 ; in simple Ascidian, 619 ; in 

 Astacus, 183, 184 ; in larva of Asterias, 

 461 ; in adult Ax/a-ias, 471 ; in adult 

 Ast, ',-i,in ///////,</, 479 ; in adult Echinus 

 esculentus, 518, 519 ; in adult Ojihinthi-l.i- 

 fragilis, 495 ; in 1'nlinliiia, 310 ; in Peri- 

 patus capensis, 171: in 7VW //</, 56; 

 function of, in Platyhelminthes, 102 



Mouth in Aurcfia identical with blastopore 

 68 



Midler's fluid, composition of. use of, 33 

 Miiller's larva, 104, 164 ; compared to a 

 Ctennphoiv, 115 



Mailer's papillae, formation of, in larva of 



Arilp]lil>.:-IIS /</,/C,_;:/</fl'S, 604 



Musca, 280 



Muscidae, 272, 278, 287 ; metamorphosis 

 of, 278-280 



Muscles, formation of, in Antedon rosacea, 

 558 ; in Callidina russeola, 426 ; in 

 Pilidium larva of Cerebratulus ln.ctcus, 

 120, 121 ; in Cyphouautes larva, 390, 391 ; 

 in arms of Ophiothrix fragttis, 498; in 

 stomodaeum of Ph/mvcra, 111 ; in blasto- 

 zooid of Urochorda, 639 ; in Urtidna 

 crassicornis, 83 ; metamorphosis of, in 

 larva of Galcrn<;-U,i ulmi, 270 



Myoblasts of JTej >//clis, 162; of Criodrilns. 

 158 



Myocoeles in Ainphio.''//* /tin<'eolatnx, 601 



Myotomes, formation of, in Amji/iiu.,-,^ 

 lanceolatus, 595 



Myriapoda, 169, 177, 245, 285; development 

 of, 280-284 



Mysidacea, 177, 219 



Mysis, 193 



Mysis larva, 213, 217 ; interpretation of, 

 213 ; of Astacidae, 213 ; of Crangonidae, 

 215 ; of Loricata, 214 ; of Thalassiniclae, 

 215 



M/iiilm, 332, 523 



Narcomedusae, 53 ; development of, 66, 67 



Xauplius lavv;i, I'S''. 054, 655 : interpreta- 

 tion of, 204, 205 ; of Apus, 201 ; of 

 Branchiopoda, 201 ; of Cirripedia, 201 ; 

 of Cladocera, 200 ; of Cyclop, 196-197 ; 

 of Euphausidacea, 203 ; of (.)str:icoda, 

 203 ; of Penaeidea, 203 ; of Penaeus, 22, 

 of Saco/lino, 202; of Stomatopod;i. 217 



Nauplius - like ancestor of Crustacea, 205, 

 212 



Nauplius stage in development of At-l/tlicrcs 

 ambloplitis, 206 ; of A slac-us, 185 



Xat'titus, 358 ; motion of, 369 



Neanic st.-igi- of development, 19, 22 



Nectocalyx of Siphonophora, 64, 66 



Nematoda, 436, 457 ; development of, 437- 

 455 



Nemertiuea, 157, 164, 166, 167, 457, 529, 

 561, 600, 661 ; development of, 118-127 



Nephridia, formation of, in Amj>hio.cs 

 lanceolatus, 600 ; in Criodrihts lacvtnn, 

 158 ; in Xi'pJtclis, 162 ; in Pluixi-aliismiKi, 

 379, 380 ; in Actinotrocha larva of Phi-- 

 onis, 381, 382 ; nature of, in Annelida, 

 157 



Nephridioblasts of Jfejihefis, 162 



Xi'pln-i'px, 213 



Nephropsidea, 177 



Nephrostome, formation of, in Phascolosomn . 

 380 



Nereidiformia, 128, 1 .">:'. 



JTereis, 129, 153, 156, 321, 333, 645; 

 development of, 155, 156 



Nerve-collar of PolygoTdius appendiculatus, 

 formation of, 147 



