thickenings or widenings at the free end (for instance Ancyrocephalus). 

 The longer feet can be of various lengths, sometimes they can even exceed 

 the length of the egg several times (many Microcotyle ). usually they are 

 equipped with a noticeable widening --a little platform at its free end. 

 This little platform can be of an irregular shape (many Dactylogyridae) , 

 or it can acquire a completely regular outline, as for instance among 

 Diplectanum with a regularly 5- to 6 -pointed little star at the end of the 

 little foot of the eggs. In a number of cases the end of the little foot forms 

 a sharply curved, hook-shaped growth (for instance among Microcotyle 

 gotoi Yamaguti). Usually the little feet of the eggs^ which have a consider- 

 able length are more or less strongly curved and, more rarely, are com- 

 pletely straight. The filament of the egg is of the same shape as the little 

 foot. In a number of cases it is shorter than the little foot (for instance 

 among Mazocraes), or more often it is absent (majority of the lowest Mono- 

 genoidea). However, among many marine types it is filiform and exceeds 

 the combined lengths of the egg and the little foot (many Microcotyle ). In 

 certain cases, the filament of the egg forms a small widening at its free 

 end. Among a number of species (for instance among Microcotyle caudata 

 Goto), the little foot of one egg fuses with the filament of another forming, 

 in such a fashion, a little chain of a varying number of eggs. Oftener the 

 feet of individual eggs merge together into a common foot of several eggs 

 (for instance Acanthocotyle). Finally, sometimes the filaments of the eggs 

 can also become agglutinated to each other (certain Microcotyle ). The 

 color of the eggs varies from bright yellow to dark brown. Usually the 

 color changes from a lighter to a darker shade at the time of formation 

 and further development of the egg. 



Among different species the sizes of the eggs fluctuate from 

 0. 02 to 0. 18 mm without including the length of the little feet and the fila- 

 ments. The latter may be many times (more than 60) the length of the 

 egg itself. In a number of cases the sizes of the eggs can vary greatly 

 within a single species. Thus, in Dactylogyrus vastator Nybelin we have 

 observed eggs from 0. 074 to 0. 126 mm in length, that is the linear in- 

 crease of size was almost double and the volume even more so. 



The manner of deposition of eggs of monogenetic trematodes 

 can be divided into two groups, the first deposits eggs into the water and 

 they fall onto the bottom or onto different objects on the bottom; the second 

 produces eggs which attach themselves to the body of the host or be- 

 come stuck in the inucous which surrounds the location of the parasite. 

 To the first group are related forms wherein the little feet and filaments 

 of the eggs are absent or, on the contrary .those which possess powerfully 

 developed offshoots from the eggs but which predominantly deposit eggs in 

 groups or by "portions." Thus, this is the majority of Dactylogyridae, 

 Polystomatidae, Diclybothriidae, and many other fresh water and marine p. 91 

 species the eggs of which are without offshoots. On the other hand, here also 



is related the often -mentioned Microcotyle gotoi Yamaguti, According to 



90 



