1916-17.] Experiments and Observations on Crustacea. 
59 
V. — Experiments and Observations on Crustacea : Part II. 
Moulting of Isopods. By John Tait, M.D., D.Sc. (From the 
Laboratory of Physiology, Edinburgh University.) Communicated 
by Professor Sir E. A. Schafer. 
(MS. received August 1, 1916. Bead November 6, 1916.) 
The moulting process in isopods has frequently attracted attention, the 
following notices on the subject having been collected : — 
1880. Schobl — Porcellio. 
1881. Weber — Trick oniseus , Haplophtkahnus. 
1883. Friedrich — Porcellio , Oniseus. 
1891. Leichmann — Porcellio, Asellus , Sphseroma. 
1895. Nemec — Ligidium, Porcellio, Typhloniscus, Trick oniseus, Haplopkthal- 
77i ns, Platyarthrus. 
1898. Schonichen — Oniseus, Porcellio, Armadillidium, Asellus. 
1901. Verhoeff — Porcellio. 
1906. Webb and Sillem — Armadillidium. 
1907. Pierce — Armadillidium. 
Zuelz er — A sell u s. 
1911. Tait — Ligia, etc. 
Wege — Asellus. 
1912. Hanko — Asellus. 
1913. Allee — Asellus. 
Herold — Ligidium, Trichoniscus, Oniseus, Philoscia, Platyarthrus, Por- 
cellio, Cylisticus, Armadillidium, Asellus. 
1914. Aubin — Porcellio. 
In practically all these papers — most contain mere incidental notices ; 
that of Herold gives most detail — comment is made on the fact that the 
moult occurs in two stages (separated by an interval of days), which is 
certainly the most striking feature of the isopodan moult. The present 
communication comprises a brief descriptive account of Ligia in relation 
to its moult, an attempt to establish a morphological side to the subject 
of moulting, and, lastly, some observations bearing on the physiology of 
the question. 
Descriptive. 
When a recently moulted Ligia is examined under the dissecting 
microscope the external covering of the animal looks beautifully clean 
and fresh. The gills are silvery white. Certain parts of the ventral 
