330 
THE CRUSTACEA. 
$ 290. 
stiff and motionless, and may be arranged under the following principal 
types. 
1. With the Cyclopidae, and Chilognatha, the spermatic particles, which 
are developed in cells, retain their cell-form to their perfect state, without 
any trace of processes or appendages. 
2. With the Decapoda, they are likewise nearly always of a granular or 
cell form, but have small, filiform, sac-like processes; sometimes they are 
divided into two portions by a constriction.© 
3. With the Mysina, Amphipoda, and Isopoda, they have the form 
of very long threads, pointed at both extremities, or with a cylindrical 
incrassation at one of them. 
They are motionless, and, upon the addition 
of water, do not roll up in a loop-like manner. 
4, With the Cirripedia, and Chilopoda, they are capillary, very lively, 
and, from contact with water, become entangled, forming loops and 
1 (9) 
rings. 
4 With Cyclopsina castor, the spermatic parti- 
cles are small, finely-granular, oval corpuscles (see 
my Beitr. zur Naturg. d. wirbellosen Th. p. 41, Taf. 
II. fig. 41-43 c., or Ann. d. Sc. Nat. XIV. 1840, 
p. 30, Pl. V. B.). As to the other Entomostraca, 
we have not yet sufficient data to say anything in 
general. But the form observed with Cyclopsina 
eastor cannot be regarded as a typical one with 
these animals, for Wagner (Wiegmann’s Arch. 
1836, I. p. 369) has observed large, filiform, flexu- 
ous, spermatic particles with Cypris. I, myself, 
have found those of Daphnia rectirostris to con- 
sist of a long, semi-circular body, which became 
motionless and disappeared by bursting on the ad- 
dition of water. Stein (Mudter’s Arch. 1842, p. 
263, Tat. XIV. fig. 37, 40) has rightly figured those 
of Glomeris as fusiform cells ; but he was less exact 
with those of Judus and Polydesmus, in describing 
them as small transparent vesicles (Lbid. fig. 36, 39.) 
With Julius subulosus, they look exactly like 
very short cylinders containing a very distinct, 
round nucleus. With Judus hispidus, they are 
of the saine form, but are not nucleated; while with 
Julus terrestris, they are conical and nucleated 
(see my notice in Muller’s Arch. 1848, p. 13). 
Those of the Siphonostoma are, also, of a celloid 
form ; see rey and Leuckart, Beitr. loc. cit. p. 
185, Taf. II. fig. 21 (Caligus). 
5 Henle (Miller's Avch. 1835, p. 603, Taf. XIV. 
fig. 12) and myself (Ibid. 1836, p. 26, Taf. III. 
fig. 23, 24) first called attention to the singular 
form of the spermatic particles of the common 
craw fish ; but, subsequently, Kélliker (Beitr. &c. 
1841, p. 7, Taf. IJ. IIL. and in the Schweizerisch. 
Denkschrift. f. d. gesammt. Naturw. VIII. 1846, 
p. 26, Taf. [I.) has shown that those of the most di- 
verse species of Bruchyura, Anomura, and Macru- 
* [-§ 290, note 7.] The spermatic particles of 
the Crustacea are the most remarkable of any in 
the whole animal kingdom. The strange, bizarre 
forms, here observed, have led to singular views as 
to their development and character. The recent 
researches of Kélliker have done much to clear up 
this intricate subject, and these researches have 
been continued by Wagner and Leuckart (Art. 
“Semen, Cyclop. Anat. and Physiol.). The most 
singular of these particles, as is well known, are those 
belonging to the higher forms of this class. The de- 
velopment and nature of these I have recently stud- 
ra, are motionless, radiated cells, one part of 
which is separated by a constriction, and prolonged 
sometimes into a' kind of peduncle; the rays 
are often only three or four in number, and the 
cells themselves are sometimes conical or cylindri- 
cal. The most simple of these spermatic particles 
are observed with Crangon vulgaris, and Palae- 
mon squilla; and, according to my own observa- 
tions, consist only of flattened cells with a short 
pointed process. 
6 Simple capilliform spermatic particles are found 
with Mysis, Oniscus, Porcellio, Idothea, and 
Gammarus ; see my researches in Miller’s Aych. 
1836, p. 27, Taf. IIL. fig. 19, 20, and Ibid. 1837, 
p. 433; also Kéddiker, Beitr. loc. cit. p. 15. This 
last naturalist (Beitr. &c. p. 14, Taf. III. fig. 28, 
29) has stated that the long capillary, but motion- 
less spermatic particles of Iphimedia obesa and 
Hyperia medusarum are terminated by a cylin- 
drical and slightly flexuous incrassation. I have 
found those of Asedlus aquaticus to be similar, 
but the cylindrical extremities were straight. 
7 The spermatic particles of the Cirripedia, which 
are simply capillary and very active when fully de- 
veloped, have been observed by me (Muller's 
Arch. 1836, p. 29), with Balanus pusillus, and 
by Kélliker (Beitr. p. 16, Taf. III. fig. 30, and 
Schweiz. Denks. loc. cit. p. 33) with, many other 
species of Balanus, and with Chthamalus, Lepas, 
and Pollicipes. Those of Lithobius and Geophi- 
dus present a remarkable aspect from their extreme 
activity, and may well be recommended for study 
from their size (Stein, in Miuller’s Arch. 1842, p. 
250, Taf. XID. XIV. fig. 19-33). Treviranus 
(Verm. Schrift. II. p. 26, Taf. VI. fig. 2, 3) has 
taken those of Scolopendra, which are bound to- 
gether in a long white cord, for a Helminth.* 
ied, and with results quite different from those of the 
authors just mentioned. My observations were made 
on those of Pagurus, Pilumnus and Astacus. 
Here, the development occurs in special cells like that 
of those of other animals, and the particle, howev- 
er singular its form, is the transformed nucleus of 
these cells. The spine-like processes lie reverted. 
on the body of the particle when this last is in the 
special cell, but become erect and prominent when 
the particle escapes. The body of the particle, 
therefore, is solid, and not hollow and nucleated, 
as has been supposed (see Kaélliter and his 
