250 
J. 0. Wakelin Barratt and G. Arnold 
solution of methylene blue for 30 to 60 minutes, rinsed in water, passed 
through a series of alcoholic liquids of increasing strength and finally 
put into absolute alcohol. They were next placed for about two minutes 
in clove oil containing about 0,1% of orange G, after whicli they were 
transferred to xylol and finally mounted in canada balsam. 
Ultimate changes produced in the testis by X rays. 
The end result of the application, in sufficient amount, of X rays to 
the testis is to cause profound changes, the seminal cells normally seen 
disappearing completely (Fig. 30). No open central area is seen in the 
seminiferous tubules, which are filled with shreddy material, made up of 
ragged Strands of lightly staining substance arranged perpendicularly to 
the basement membrane and therefore directed more or less radially. 
These Strands, which are more marked near the centre of the tubule, be- 
coming less well defined towards the basement membrane, are now usuallv 
regarded as representing the cytoplasm of the numerous large Sertolian nuclei 
which are seen disposed chiefly near the basement membrane. Between 
the strands are empty spaces in which a few masses of fatty material of 
more or less globular shape and varying size are met with. These are similar 
to the masses seen in what will next be described as the penultimate stage, 
and will therefore not be further referred to at present. The basement 
membrane is readily seen and appears to be normal in aspect. 
Viewed under a higher magnification the shreddy material above 
referred to, which stains with acid dyes, exhibits much diversity of aspect, 
for the most part arranged in the form of thin sheets, some short, others 
extending from the basement membrane nearly to the centre of the tubule. 
Although most of the strands are disposed radially, some are irregularly 
arranged, forming a coarse meshwork. The material of w T hich the strands 
are composed can generally be recognized to be finely granulär in aspect. 
The nuclei, which liave a sharply defined nuclear membrane, present 
chromatin which is evenly distributed in the form of extremely fine 
granules throughout its substance (Fig. 13). Only one nucleolus is present, 
which is darkly stained, and relatively large. The majority of the nuclei 
exhibit what appears to be a fold. The liniits of the cytoplasm surrounding 
the nuclei cannot be accurately ascertained. No large cliromatin masses 
can be seen in the nuclei. 
In the penultimate stage the appearance of the tubules is in part 
similar to that just described, differing from it, however, chiefly in the 
circumstance that the tubule is largely occupied by necrotic material 
and fatty masses, some of which are of considerable size (Fig. 31). The 
