



Fig. 24. —Transverse section 

 through normal trout embryo, a con- 

 siderable distance in front of the vent. 

 Compare with Fig. 27 (union by pos- 

 terior part of body). Other references 

 under PI. I. fig. 1. ( v 14.) 



Fig. 27. — Transverse section corresponding with Fig. 24, 

 but through a double monster of the type illustrated in 

 PI. II. fig. 10. Figs. 28, 29, and 31 are from the same 

 series. At this level the two intestinal canals are widelv 

 separated. For relations of Wolffian ducts, etc., see pp. 

 22. 23 and PI. XIX. figs 76-79. (x 14.) 



Fig. 25. — Transverse section as m 

 Fig. 24, but a little further back. 

 Compare with Fig. 28 (union by pos- 

 terior part of body). Other references 

 under PI. I. fig. 1. (x 14.) 



I i'.. 28. — Transverse section of the same double monster 

 a- m Fig. 27, but a little further back in the series. The 

 intestine is now single, but has two mesenteries. The Wolffian 

 bodies and ducts are coming together bv then inner, 01 

 adjacent, sides. Compare with Fig. 25 (normal). Other 

 Fig. 27. ( x 14.) 



Fig. 26. — Transverse section, as in 

 the two preceding figures, but passing 

 just m front of the vent. The Wolffian 

 ducts have opened into the bladder. 

 which is seen lying dorsal to the 

 rectum. Compare with Fig. 29 (union 

 by posterior part of body). Other 

 references under PI. I. fig. 1. i 14.) 



FlG. 29. — Transverse section through same double mon- 

 sti 1 as in Figs. 27 and 23, but further back in the series. 

 Compare with Fig. 26 (normal). The adjacent Wolffian 

 ducts have opened into a first bladder, while the outer ducts 

 have not yet reached the second one, which lies posterior to 

 the other. These relations are explained on p. 23. Other 

 references under Fig. 27. (xi4.) 



PL. VI. 



