Description | Slide shows two diagrams of the 'Trochophores of Patella at different stages.' Diagrams are labelled 'A' and 'B'. Title below diagrams reads 'Fig. 573, - A and B, Trochophores of Patella at different stages. In A are to be seen the circular blastopore and the two-foot elevations; in B the blastopore is drawn out, at the sides of it are the two mesoderm bands. (From Korschelt and Heider, after Patten.' |