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J. S. KINGSLEY. 
(a fresh-water form) six glandular spots on either side of the 
abdomen, which later unite to form a tube, though he did not 
find the place where it opened. Weber (’ 79 , p. 237) mentions 
and (’ 81 , pp. 608 — 612) describes and figures tubes emptying 
into the hinder intestine in Trichoniscus, and says that they 
also occur in other Oniscidae. He also states that he found 
depositions of urates, a fact which at once deprives the opinion 
of Wrzesniowski (’ 79 , pp. 514, 515) of much of its force. The 
investigations of Nebeski (’ 80 , pp. 122 — 127) are the most 
interesting. This author describes certain organs arising at 
the beginning of the hind gut of certain Amphipods. In the 
strictly aquatic genera these glands are small, but in the more 
terrestrial Gammarus they become well developed, while in 
Orchestia, a form living in the sand above high tide, they are 
very long and tubular, and the histology shows that they have 
active secretory or excretory functions. In position and origin 
they correspond closely with the Malpighian tubes. His series 
on pi. ii, fig. 14, is very instructive. 
Nebeski’s observations, however, are not conclusive, for he 
shows the rudiments of the same organs in Amphipodous 
genera which are solely aquatic. Gamroth (’ 78 , pi. x, fig. 14) 
figures two globular glands occupying the same position in 
Caprella which he regards as urinary, and Haller (’ 80 , p. 384), 
studying the same genus, agrees with him. These forms are 
all confined to the Tetradecapods, and so far as I am aware, no 
similar organs have been found in any other Crustacea. Still 
they may be derived from an ancestor common to them and to 
all the Trackeates. These ancestral glands may have been 
very small, possibly mere glandular surfaces, and changed con- 
ditions in life have caused their increased development. A 
somewhat parallel case is that noted by Grobben (’ 80 ) that the 
antennal gland differs in its length and complication in the 
salt- and in the fresh-water members of the same genera of 
Copepoda. 
This of course is but analogy. It seems at present as if 
these organs had arisen in the Crustacea independently of their 
existence in other Arthropods. If this be the case, their 
