egg capsules formed by the breaking up of the reticular uterus. The 
number of eggs in a capsule varies with different species and may 
vary in one species. In the case of worms of this genus, one may find, 
in the feces of infested animals, segments, egg capsules or individual 
eggs. In D. caninum of dogs and cats, the egg capsule (Fig. 4) may 
contain 5 to 20 or more eggs, the egg (Fig. 5) being spherical, 43 to 
54 microns in diameter and with an onchosphere 25 to 36 microns in 
diameter. In D. sexcoronatum of dogs and cats, the egg capsule may 
Fig. 7. Diphyllobothrium latum. Egg. x 680. From Magath, 1919. 
contain 2 to 15 eggs, the eggs being spherical and 21 microns in 
diameter. 
The eggs of tapeworms of the genus Mesocestoides are ovoid and 
have two very thin shells. The egg of M. lineatus (Fig. 6), which 
appears to be identical with M. litteratus, of dogs, cats and foxes, is 
40 to 60 microns long by 35 to 43 microns wide. 
The eggs of Diphyllobothrium (Dibothriocephalus or Bothrioce- 
phalus) are elliptical and provided with a small operculum or lid at 
Fig. 8. Opisthorchis pseudofelineus. Egg. Enlarged. From Barker, 1911. 
one end. The egg of D. latum (Fig. 7) of dogs, cats and foxes is 
68 to 71 microns long by 44 to. 45 microns wide, according to texts. 
Magath finds a range of 55 to 76 microns in length by 41 to 56 
microns in width. In general the figures given here for egg sizes are 
those given in texts. As a matter of fact, careful measurement of a 
large number of eggs will usually show some eggs which lie outside of 
the range of measurement given. 
Fluke eggs are usually more or less oval in shape, with an 
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