November 2, 1917] 



SCIENCE 



441 



" Outlines of Zoology," 1913, makes a similar 

 remark. Thomson, in speaking of the char- 

 acteristics of the Arthropoda, on page 281, 

 says: "Ciliated epithelium is almost always 

 absent." 



While working on the structure of the male 

 reproductive organs of certain Decapoda," the 

 author has found good examples of ciliated 

 epithelium in the vasa deferentia of the fol- 

 lowing forms : the Pacific coast crayfish 

 Astacus leniusculus, the Puget Sound hermit 

 crab Pagurus seiosus, the Atlantic coast lob- 

 ster, Homarus americanus, and the spiny lob- 

 ster of the California coast, Panulirus inter- 

 ruytus. 



The vasa deferentia of these Crustacea were 

 fixed in various fluids (Hermann's, Flem- 

 ming's, Bouin's and formaldehyde), and the 

 section were cut 5 a^ in thickness. These pre- 

 pared sections formed the basis for the ob- 

 servations herein recorded. The author tried 

 to tease out the living epithelial cells from 

 the vas deferens of Astacus leniusculus in 

 physiological salt solution, Ringer's solution 

 as well as in the body fluids of the crayfish, 

 with a view towards observing ciliary move- 

 ment in the living cells, but along this line 

 of experimentation little success was met 

 with. In the first place, the heavy secretions 

 of the vas deferens, coupled with the refraction 

 of the cell structures, masks any clear-cut ob- 

 servations. Secondly, the cytoplasm of the 

 epithelial cells is so frail that it goes all to 

 pieces upon the application of the least amount 

 of pressure. The writer had, therefore, to 

 rely solely on the prepared slides. However, 

 these epithelial cells are so distinctly and so 

 characteristically ciliated in the fixed material, 

 that they are very convincing and appear to 

 allow of no other interpretation. 



In all the forms mentioned the inner lining 

 of the vas deferens consists of a layer of cil- 

 iated epithelium, which is made up mainly 

 of columnar cells. This epithelium is more or 



2 A fuller account of these studies is soon to ap- 

 pear in the publications of the Puget Sound Ma- 

 rine Station, Vol. No. 26, under the title of ' ' Male 

 Eeproductive Organs of Decapoda, with Special 

 Reference to Puget Sound Forms." 



less glandular in nature and manufactures a 

 thick, viscid secretion that forms the sperma- 

 tophoral pouches as well as the sperm-preserv- 

 ing fluid which is commonly found in the 

 Decapoda. 



In Astacus leniusculus the epithelial lining 

 is more or less miiform throughout the vas 

 deferent tube, while in the other forms it be- 

 comes somewhat modified. 



In Paragus setosus, the epithelial cells be- 

 come concentrated at one pole of the vas defer- 

 ens and here they are very much elongated, 

 columnar cells and bear fine examples of cilia. 

 This region of the epithelium seems to be es- 

 pecially adapted for manufactming the secret- 

 ing fluid. The lining epithelium of the rest 

 of the vas deferens tube consists of ciliated 

 cuboidal cells. 



In Homarus americanus the epithelium be- 

 comes convoluted in numerous places of the 

 distal end of the vas deferens, thus affording 

 a larger secreting sui-face. Wherever these 

 convolutions occur, the cells are usually larger, 

 and contain longer cilia than in other regions. 

 Herrick^ who has made an extensive study of 

 the lobster does not mention ciliated epithel- 

 ium in the vasa deferentia. In good prepar- 

 ations, the ciliated epithelium is so distinct 

 that one is able to make clear microphoto- 

 graphs of these structures without any diffi- 

 culty. 



In the spiny lobster Panulirus interruptus, 

 the finest examples of ciliated epithelium were 

 found. In this crustacean the vas deferens 

 is very long and is lined by an inner layer of 

 ciliated columnar epithelial cells. At one 

 point in the vas deferent tube this epithelial 

 lining dips inward into the cavity of the 

 tube and becomes profusely convoluted into a 

 mass of simple tubular glands. In cross sec- 

 tions, some of these glands may be seen cut 

 across to show the central lumen completely 

 surrounded by the epithelial cells. In such 

 cases, the long cilia are very distinctly seen 

 extending from the free surfaces of the cells 

 into the interior of the lumen. 



» Herrick, F. H., ' ' Natural History of the Amer- 

 ican Lobster," BuU. TJ. S. Bur. of Fisheries, Vol. 

 XXIX., 1909. 



