MILLER — CONTRIBUTIONS FROM ANATOMICAL LABORATORY. 205 



the nucleus and protoplasm of every cell, are usually found in the 

 corners of the single cells, so that several plugs lie together and are 

 found in a single capillary mesh. Still, many cells are also found 

 which bear their granular continuations nearer the middle and com- 

 pletely fill a capillary mesh." , 



Williams says: 



"The epithelial scales which cover the capillary areas of the lung 

 of the newt (parts which coincide with air-cells of the mammalian 

 lung) lose not only the external appendages (cilia), but also their 

 internal parts (nuclei and granules). This successive reduction leaves 

 nothing but a hyaline involucrum enclosing a pellucid fluid." 



Stirling also investigated the Inng of the newt and says : 

 "The arrangement of these cells is curious. They lie in groups, 

 and the large nuclei occupy the small spaces left between the blood- 

 capillary network, whilst the thin plates of each cell cover the cap- 

 illary wall. The result of this arrangement is that the air in the 

 lung is separated from the blood-stream merely by the cell plate of 

 these cells and the squames which form the capillary wall." 



If now the remaining lung be carefully removed and stained 

 by means of nitrate of silver, the outline of the cells and their 

 nuclei will be brought into view, PL 4, fig. 4, shows the out- 

 line of the cells, also that of the islands in which the nuclei and 

 protoplasmic part of the cells are situated. PL 5, fig, 5, shows 

 the relation of the nuclei and protoplasm to the cell boundaries 

 in a case where several nuclei are found in a single mesh of the 

 capillary network. Sometimes we find a single nucleus filling 

 the whole mesh and lying near the center of the cell, as shown 

 in PL 5, fig. 6. Sometimes we find the cell boundaries appar- 

 ently cutting through a nucleus, as we see them doing in a few 

 instances in PL 5, fig. 7, This is merely a condition due to the 

 ovei^lapping of one cell by another, as was shown by Schmidt 

 in the case of the frog, A projection of the relation of the 

 nucleus to the boundary lines is shown in PL 5, fig, 8. 



To demonstrate the presence of cilia the animals were killed 

 by pithing ; the lung was then removed and cut open along both 

 the artery and the vein. The cilia were seen to better advantage 

 at the edges of the preparation than on the surface. Ciliated 



