JOURNAL OF MICROSCOPICAL SCIENCE. 



EXPLANATION OF PLATE VI, 



Illustrating Dr. E. Klein^s Observations on the Early De- 

 velopment of the Common Trout. 



Fig. 1. — Vertical section through a blastoderm 3 days old. 



Fig. 2. — Similar section through a blastoderm 8 days old. 



Fig. 3. — Vertical section through a blastoderm 9 days old. 



Fig. 4.— 12 days old. a . , ^ ,. , 



-!?.„ c TO J ij C The section does not comprise the centre of the 



tiG. 5. — 13 days old. ^ 1 1 . j ^ 



„ i blastoderm. 



Fig. 6.— 14 days old. J 



Fig. 7. — Vertical section through an excentric portion of blastoderm 

 13 days old. 



Fig. 8. — Vertical section through the same blastoderm as in the preced- 

 ing figure, only nearer to the centre. 



Fig. 9. — Vertical section through the very edge of a blastoderm 14 days 

 old. 



Fig. 10. — From a vertical section through an excentric portion of para- 

 blast of a blastoderm 13 days old. 

 All figures were drawn with camera lucida. 

 Figs. 1, 2, 3, 4, 5, 6 with Hartnack's Oc. ii, Obj. 4. 

 Fig. 7 „ „ Oc. ii, Obj. 8. 



Figs. 8, 9, and 10 „ „ Oc. iii, Obj. 8. 



The meaning of the letters is as follows : 



a. Archiblast. 



p. Parablast. 



y. Yolk. 



sc. Segmentation cavity. 



s. Surface of parablast. 



/. Ordinary sized elements on the floor of segmentation cavity. 



/. Large elements of the same kind. 



fi. Nucleus. 



fii. Transparent cells derived from the parablast. 



d. Cavities in the yolk (fat-globules ?). 



