BUDDING IN HYDRA. 



211 



the secretion of the digestive fluid, which aids in the breaking up 

 of the food in the enteron, while those endodermal cells in the 

 region of growth, " the formation of buds and sexual organs," 

 are the most active in ingesting the partly digested food from the 

 enteron and preparing it for diffusion into the ectodermal cells. 



The ectoderm and endoderm in the early formation of the bud, 

 which are quite uniform, soon become differentiated into two dis- 



FIG. i. Longitudinal section of hydra showing the origin of bud at a. 



FIG. 2. Part of preceding figure at a. X 80. 



FIG. 3. Longitudinal section through wall of hydra showing curvature of 

 mesoglea and beginning of enteron in forming bud. m, mesoglea ; a, enteron. 



FIG. 4. Stage of development a little later than preceding, a, the point 

 of junction between parent and bud. 



FIG. 5. A portion of preceding figure at a, which includes the entire area 

 in the formation of bud. end., endoderm. X 90. 



FIG. 6. Diagram of a longitudinal section of parent hydra with bud. 

 a, active growing region in formation of bud. 



