Curtis, — Planaria. 
PLATE 18. 
(The figures of this plate are reduced two thirds in the reproduction.) 
Fig. 53. A semi-diagrammatic figure of an early stage in the development of the 
reproductive organs. Outlines of body, ovaries, and testes from a 
camera drawing of a whole preparation. The testes are only shown 
on one side. Zeiss A* X 4. 
Fig. 54. Semi-diagrammatic figure constructed in the same way as the last, of a 
stage in which the atrium (a) is just appearing and the cord of cells 
{oy) has just appeared along the line of the future oviduct. Zeiss 
A^ X 4. 
Fig. 55. Semi-diagrammatic figure like the last, of a stage at which the oviduct 
has appeared along the line where the cord of cells previously lay, while 
with it are connected the incipient yolk glands {y). The parts of the 
atrium can he seen and also portions of the vasa deferentia, but the 
connections of the vasa deferentia and oviducts with the atrium have 
not been attained. Zeiss A* X 4. 
Fig. 60. Outline of the organs appearing in a transverse section of a sexually 
mature P. maculata, taken midway between the pharynx and the 
ovaries to show the lateral and vertical extent of testes and yolk glands. 
Zeiss A X 1. 
