30 



CELL DIFFERENTIATION AND THE ELEMENTARY TISSUES 



more accurately be termed transitional, page 28, or stratified, b. Some portions 

 of the generative apparatus in the male, viz., lining the "vasa efferentia" of 

 the testicle, and their prolongations as far as the lower end of the epididymis, 

 and much of the vas deferens; in the female, c, commencing about the middle 



FIG. 33. Specialized Pigmented Epithelial Cells of Retina. 



of the neck of the uterus, and extending throughout the uterus and Fallopian 

 tubes to their fimbriated extremities, and even for a short distance on the per- 

 itoneal surface of the latter, d. The ventricles of the brain and the central 

 canal of the spinal cord are clothed with ciliated epithelium in the child, but 

 in the adult this epithelium is limited to the central canal of the cord. 



FIG. 34- 



FIG. 35. 



FIG. 34. Spheroidal Ciliated Cells from the Mouth of the Frog. X 300 diameters. (Sharpey.) 

 FIG. 35. Ciliated Epithelium from the Human Trachea, a, Large, fully formed cell, b, 

 shorter cell; c, developing cells with more than one nucleus. (Cadiat.) 



The cilia themselves are fine rounded or flattened homogeneous processes. 

 According to some observers these processes are connected with longitudinal 

 fibers which pass to the other end of the cell, but which are not connected w r ith 

 the nucleus. 



