OF co us^r . < 



PI. XXII. figs. 94-96, PI. XXIV. I : , im drawings made 



l>y the atith.-: and re cased on the study of numerous series of section*. All the otln ma figures 



are from phnfnniarographs of specimens or sections. 



trout emljrj c.. and of I 

 of double i 



Ph. ! 



Jkfl^** IIMM-* t*i 



QWWMV * "f 



hwiaotfiMI to vr 



.. PI. VI. figs. 24-26. 



"rue outturn "f normal trout embryo at the Mint 

 tm# m U .-(.-.,- t M UM monstrosities doocribod. 



f the Utter, shown in 



<. 21-91. 

 BsMBBtal oouticsM of nnmul trout embryo, M above. 



a^. 87-1W; loo PI. VII. * *>-3l 



TntMVOTM OMtiMO Of dhbfc IMMtan Vtlfc MMOB to 



pastoriuf pon 



girdle and fin cartilages in an e> imjile from Class 

 (union in pectoral region, inner pect 'vg present 



but united). Figs. 69-72 are diagrams to iUootnte the 

 cavities of the brain in a normal embryo aswi 

 Mojotor* belonging to Classes I. and II. 



if*. 78-81. 



Figs. 7-%- 75 illustrate the heart in a normal embryo and 

 in double monsters hrtnaglag to Class III. 

 pectoral region, adjacent peetora] tins not !> 

 sented) and Class IV. (uniou in pectoral region, adjacent 

 pectoral fins being present but nulUd). Mas. ' 

 Ulu.tr.te the posterior ends of the Wolffian Jucta, the 

 blxidon nd urinary pores in a normal embryo .<.-. 



H VII rtg. . 



Ti 



OB pp. 33 34 i so* alac Pta. X.xil. XX111. fig*, in W 

 PU. VIII. -IX. tigs. 36^38. 



v Transverse section through the heatKof a doable monster 

 union of the twin brains >n theVegion of the optic 





lead of a double monster 

 >rains in the region of the optic 





PI. XII. figs. 43^46. 



m i * 





u uf tb twin brain* in the region of the medulla 

 (CW- 



Pls. XV.-XVI. figs. 52-55. 



Horizontal sections of a dnbl 

 the pectoral region, inner Doctoral 

 (Claw III.). 



PI. XVI 1. tigs. 56-CS. 



Diagrams to illustrate : the cartilaginous cranial, hyo- 

 mandibular, and vertebral, skeletal elements in normal 

 trout embryos, and in double monsters belonging to 

 Classes I. and II. (union of the twin brains in the region 

 of the optic lobes or of the medulla). 



PI. XVIII. figs. 64-72. 



Figs. 64 and 65jilustrate the visceral arch cartilage*, and 

 Fins. 67_anA-<8tlie 'vascular system in double moo 



Fig. 66 show* th i 



belonging to Classes V. and VI. (union 



Tt.tm.n 



fl saowi 



Figs. 83-8' 

 yan 





 U. and IV 



re of Ik* tripl* OMHMttor 



alimentary and urinary stnctn 



, 



The figures illustrate cyclopia (pp. 40-45) and super- 

 numerary eyes (pp. 59, 60). 



PI. XXV. figs. 107-110. 



Transverse sections through the ocular region in cyclofOa 

 and semicyclopia (p. 44). 



PL XXVI. figs. 111-114. 



Fig. Ill follows Fig. 110 in illustrating semicyclopia: 

 Fig. 112 shows the atropjuc head referred-^ on p. 61 . 

 Fig. 113 is a seeti"n aj<"flj nliosa7ir1ifTintcu\liriiif . and 

 Fig. 1 14, secflSnbehind the pectoral fin* i* a double 



