532 
PROTOZOA. 
11. Metschnikoff, E. Zur Entwickelungsgeschichte der Kalksch- 
wiimme. Z. wiss. Zool. xxiv. pp. 1-14, pi. i. ; Ann. N. H. (4) xvi. 
pp. 41-43, pi. ii. 
Distribution j Local Lists, 
McIntosh gives a list of the Spongiidce of St, Andrew’s ; Ann. N. H. 
(4) xiii. pp. 142-145. The Sponges are also noticed in the papers of 
Whiteaves and Verrill quoted above [p. 493]. O. Schmidt has 
recorded the siliceous, and E. Hacked the gelatinous and calcareous, 
Sponges collected during the 2nd German Polar expedition (Zweite 
Deutsche Nordpolarfahrt, ii, pp. 428-436). 
Embryology , Anatomy, ^x. 
Carter (2 Sc 3) demonstrates the existence o^ flagellate cells (“ Spon- 
gozoa^' C.) in Ilalisarca dajardini and lohularis, and describes his experi- 
ments in colouring them by feeding them with carmine. He has traced 
the connection between the “ ampullaceous sacs,” formed by these “ Spon- 
gozoa,” with the pores or pore-Canals, but was not able to determine their 
mode of communication with the excretory system. The presumed 
analogy between Sponges and compound Ascidians is also discussed, and 
the theory of the “Spongozoa” or flagollato colls as “ indi/idualizcd 
animals” still adhered to. The “ soed-liko ” reproductive body (4) o£ the 
freshwater sponges is interpreted as “ an assemblage of ova, which are at 
once developed together into a young Spongilla.^' The origin of the 
young spicules of different types in true nucleated cells is confirmed on 
fresh specimens of Esperia cegagropila, Johnst., and Micraciona armata, 
Bk. (4 & 7). Carter also figures (4) the presumed spermatozoids of 
Microciona atrosanguinea, described by himself in 1870; he further 
describes and figures spermatozoid bodies discovered (dead) in Grantia 
compressa, and (living) in Halisarca dujardini ; but these are the only 
instances in which he has met with anything like spermatozoa, though 
he has examined living sponges hundreds of times under the microscope. 
Leidy (Remarks on Sponges, P. Ac. Philad. 1874, p. 144) supports 
the views of Carter, regarding the sponges “ as compound flagellated 
Infusoria.^'* 
Metscunikoff’s studies of the evolution of Calcareous sponges (11) 
have essentially modified HackePs statements [Zool. Rec. ix. p. 474], 
which were apparently chiefly based on the comparison of the structure 
of the larva with that of the young sponge, without any positive know- 
ledge of the transformations by which the latter is produced. The 
larva of Sycon cilia turn {Sycandra raphanus) is almost globular, but 
formed of two sub-equal halves, the anterior consisting of cylindrical 
flagellate cells, the posterior of roundish cells without cilia. The outer 
wall of the body is formed by fusion of these non-flagellate cells, 
and in this “ syncytium ” the calcareous spicula are developed ; the cili- 
gerous portion is invaginated and becomes the endoderm. The anterior 
opening resulting from this invagination is only transitory ; the fixed 
young sponge is completely closed up, apparently solid, and consists of 
