THE EMBRYO 



303 



divide by either a transverse or an oblique wall. Further divisions, 

 which do not follow any definite pattern, give rise to a mass of five 

 to ten cells, some of which begin to enlarge enormously and assume 

 a haustorial function. One or two cells divide transversely to form 



Q 



U 



Fig. 174. Development of embryo in Vanda parviflora (A-O) ana Cymbiiium 

 bicolor (P-U). A, Vanda, two-celled proembryo with basal cell dividing. B, 

 three-celled proembryo. C, same, upper cell dividing. D, vertical division of 

 primary suspensor cell. E-J, development of eight-celled suspensor by three verti- 

 cal divisions of primary suspensor cell. K, optical t.s. through suspensor region of 

 a stage similar to J. L-N, stages in elongation of suspensor cells. 0, mature 

 embryo with remnants of suspensor haustoria. P-R, Cymbidium, early stages in 

 development of embryo. S-U, later stages, showing maximum elongation of sus- 

 pensor cells. (After Swamy, 19^2a,b.) 



