402 Charles R. Stockard. 
Sections oF WruLuL DIFFERENTIATED FREE LENSES 
Fiag. 5 A-section of two free lateral lenses in the nineteen day embryo shown by 
fig. 1.; no trace of optic cups exists. This embryo has two ears of unequal size. 
Fria. 6 Section of the head of nineteen day embryo, first thirty-six hours in 9 
per cent alcohol. Three free lenses, A. B. and C are shown, a defective optic cup 
completely separated from the lenses is deeply buried in the head tissues of a more 
posterior region, see fig. 27. 
Fic. 7 Section of the anterior tip of the head of a nineteen day embryo from 9 
per cent alcohol. The upper right lens protrudes from a defective eye shown in 
more posterior sections, while the lower lens, F’., is free, being in no way associated 
with an eye. 
Fic. 8 A somewhat sagittal section of a similarly treated embryo of same age, 
showing another free lens, p, a pigment spot. 
Fic. 9 An anterior and fig. 10 a more posterior section through the eye region 
of a nineteen day embryo treated with alcohol. The diagram, fig. 11, shows the 
plane of both sections. Fig. 4 shows the same embryo from life; the eyes in the 
sections are reversed by the microscope. Two optic cups are present each with a 
lens, A. and D, while two other perfectly differentiated lenses, B and C, are not 
connected with an optic part. 
Fria. 12. Asection through the anterior tip of a pointed-headed eyeless embryo 
nineteen days old. The lens is well differentiated; the ears in this specimen are 
scarcely formed. 
Fra. 13. A section of a nineteen day embryo showing a small defective choroid 
cup with a lens, and a second-accessory lens is near by. 
