Bull. U. S. B. F., 1926. (Doc. 1015.) 
Fig. 25. — Embryology of the Elbe River smelt, from Ehrenbaum. 1. Mature, unfertilized egg, collected before absorp- 
tion of water. Diameter 0.75 millimeter. Ip. The pores of the zona radiata externa of the egg greatly magnified. 
2. Mature egg immediately after placing in water containing sperm; the zona radiata externa is ruptured and on the 
point of turning back on itself, whereby it remains only near the micropile, suspending the egg. 3. Egg with devel- 
oped (yellowish) transparent yolk, 6 hours after fertilization. Diameter 0.90 millimeter. 4. Egg with embryo of 9 
days; large yolk and few oil globules. 5. Smelt larva immediately after hatching on April 19. Length 5.5 millime- 
ters. 5 a. Showing underview of anterior portion of the same larva with its inferior mouth and extended pectoral 
fins. 5b. Posterior portion of same larva greatly magnified, also the corda cells. 5c. Underview of the corda of the 
same larva. 6. Smelt larva of Apiil 24, 6 days old. Length 6.3 millimeters. 6a. Anterior portion of the same larva. 
7. Larva of May 27, 15.5 millimeters long. 8. Larva of June 17, 28 millimeters long 
