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J. 0. Wakelin Barratt and G. Arnold 
brane is generally absent, and tlie nuclear chromatin usually Condensed 
and irregulär in outline. Some reduction in size appears to accompany 
necrosis. The degree to which the necrotic material stains varies from 
very light tinting to an exceedingly dark colouration. These changes are 
similar to, but less frequent, than tliose occurring in the X rayed tissues, 
about to be described. 
2. Fatty globales are met with under two aspects: a) collections of 
small globules chiefly disposed near the lumen of the tubules and b) larger 
granules, some single, some forming small aggregations situated near the 
basement membrane. 
a) These occur in the cytoplasm of spermatids, particularly in cast- 
off cytoplasm, first appearing when the liead of the Spermatozoon is 
formed (Fig. 32). The globules are all of about the same size. that is 
to say, about 3 u in diameter. Their number is variable, a dozen or 
more being usually present. For the most part they stain unequally 
with osmic acid. These collections are mostly found near the lumen 
of the tubule, they are less frequent and fewer in number in the middle 
portion of the tubules and are scantv near the basement membrane. 
The individual globules lie very close together. 
b) Fatty globules of the second dass are sparse in number and usually 
occur only in a minority of the tubules. They vary in size from 2 u to 12 p, 
the larger size generally predominating (Fig. 32). Some of these globules 
are spherical, others present an uneven but still rounded outline, the 
latter being evidentlv formed by the coalescence of smaller masses. The 
appearance of small vacuoles near the edge, as if a portion of the fatty 
globale liad been scooped out, is not uncommon. These fatty glpbules 
appear to arise within the cytoplasm of young spermatids, which are 
placed nearer the basement membrane than usual, and exliibit fatty 
change in an exaggerated degree. 
The above degenerative changes are most easily observed during 
the noncopulatory periods when the testes diminish in size and are with- 
drawn into the abdominal cavity. When the testes become enlarged 
and descend into the scrotum, the germinal cells multiplying rapidly and 
abundant production of spermatozoa taking place, such degenerative 
changes become reduced to a minimum. These changes do not appear 
to have been described by those observers who have investigated the 
normal course of development of seminal cells. 
In addition some of the further changes met with after exposure 
to X rays, described in the next section, are occasionally observed in 
normal testes. Thus multinucleate cells occur, thougli rarely. Enlarge- 
