§2 E. H. STRICKLAND 
Pérez (’06) found, that in the case of crabs, the presence of 
Thelohania sp. in the ovary caused the parent to reabsorb its 
eges. There are no indications in Simuliid larvae that the repro- 
ductive organs are actually infected. Since they are absent when 
but one myxosporidium is present, which may be situated ven- 
trally to the alimentary tract, it seems more probable that, as 
in the case of Trichonympha spp. in Termites, the presence of 
the parasites causes suppression in the development of the re- 
productive organs without actually coming into contact with 
them. 
In no preparations was there any noticeable hypertrophy of 
the alimentary tract, as seen by Léger (97) in 8. ornatum when 
parasitised by G. varians Léger or by myself (711) in 8. hirtipes 
when parasitized by various Myxosporidians. There was, how- 
ever, a varying effect upon the histoblasts, from an almost com- 
plete atrophy to hardly any noticeable reduction in size (pl. 6, 
fig. 6). For a fuller account of the histoblasts, and the effects 
of the parasites upon them, I would refer the reader to my former 
paper (711). 
From numerous observations, I feel convinced that parasitised 
larvae never pass through the pupal to the adult stage. Un- 
fortunately, owing to the difficulty of keeping these larvae alive 
under artificial conditions, I am unable to make this statement 
with absolute certainty, especially as evidence goes to show that 
in the infection of allied insect larvae by Glugeid parasites the 
host does not always suffer. In all of the latter cases, however, 
the parasite belongs to the family Nosematidae. The follow- 
ing is a brief account of two interesting species of this family. 
In 1903 Simond described a Nosema sp. parasite of the larva 
of the yellow fever mosquito, Stegomyia fasciata Theob. from 
Rio de Janeiro, in which he found two distinct types of spores. 
The most numerous spore was unicolored and measured 3 to 
5u x 2 to 3u. These, he states, dehisced within the host and 
thus caused auto-infection. This is the only case in which reg- 
ular auto-infection has been described. Less frequently he found 
brown spores, which were less symmetrical in form and gave 
rise to an attenuated brown filament, which was occasionally 
