No. I.] 



GAR-PIKE AND STURGEON. 



13 



The accompanying figure (Fig. 2) shows in side view the 

 natural position assumed by the embryo of Lepidosteus during 

 its development : a, b, and c represent early stages of segmen- 

 tation ; d, early growth of blastoderm cap ; e, f, and g, gastru- 

 lation ; //, early embryo (the heart region is now at the animal 

 pole of the e.gg and the blastopore in a position a little below 

 the equatorial line) ; i, embryo of 92 hours (sagittal axis of em- 

 bryo has now become horizontal); j\ the horizontal projection 

 of the same embryo ; /, embryo of 130 hours (region of embryo 



Fig. 2. 



near pronephic tubules is now uppermost); k, same in hori- 

 zontal projection. The positions assumed by the developing 

 Acipenser are essentially the same as in the above figures ; the 

 only stage of which the author is doubtful is that of the early 

 embryo, h. 



The eggs of Lepidosteus and Acipenser compared with those 

 of Teleosts are exceedingly large in size, and in their pigmented 

 character and mode of early development they are strongly 

 suggestive of amphibian. The following comparison may be 

 given of their general characters : — 



