EMBRYOLOGY. 
Tun, 3 
Lee (12) describes fully a sense-organ in Salpa, mentioned in 1876 
by Ussow. There are in S. mucronata (aggregated form) two organs, one 
on each side, near the anterior end. Each consists of a tuft of sense- 
oells on the end of a nerve, and surrounded by a calyx of supporting cells. 
He considers that the organ is a hydrometric apparatus, which may have 
been once a taste bulb. 
Korotneff (10) describes the minute structure of Dolchinia mirabilis , 
a new member of the Cyclomyaria , allied to Doliolum and to Anchinia. 
It is a colony formed of a gelatinous tube, bearing the ascidiozooids, which, 
however, are very slightly attached and readily become free. The ascidio- 
zooids are arranged symmetrically, the youngest being close to the sides 
of a longitudinal median superior groove, and the oldest furthest from that 
groove. The inferior side of the colony is free from zooids. Migrating 
buds may be found in any part between the ascidiozooids. The shape of 
the ascidiozooids and their general structure is like that of Doliolum ; and 
as the muscular system is well developed, movements are definite. The 
sexual ascidiozooids are hermaphrodite. The blastozooid form which 
must produce the primary buds, is not yet known. The buds take up a 
secondary position on the gelatinous tube, which appears to correspond 
to the large tail-like process of the nurse-form of Doliolum. 
Mingazzini (14) gives the results of some experiments on the regene- 
ration of lost parts made at Naples on Ciona intestinalis. 
EMBRYOLOGY. 
Salensky (20) has now published the third section of his important 
memoir on the embryonic development of Pyrosoma, dealing with the 
formation of the tetrazooid embryo and the development of the first 
ascidiozooids. One interesting point he shows is, that in the embryo the 
stigmata at first are at right angles to the endostyle, but become in the 
adult parallel to the endostyle and to the longitudinal axis of the body, 
the body changing its long axis and the endostyle moving to a new posi- 
tion at right angles to its embryonic condition, while the mouth forms in 
the middle of the surface previously occupied by the endostyle ; so that 
what seemed ventral (endostylar) in embryo becomes anterior (oral) in 
adult. Therefore the longitudinal slits of the adult are really when first 
formed in embryo primary stigmata at right angles to endostyle. Of 
epiblastic origin are : the test (in part), the nervous system, and the 
peribranchial cavities. From the mesoblast arise : the heart and peri- 
cardium, the elaeoblast and other problematical organs, the muscles, and 
the stolonial mesoblast. The development of the enteric cavity in the 
Cyathozooid and in the Ascidiozooids is described. Salensky considers 
that the mono-ovular condition of Salpa and Pyrosoma is derived from 
a poly-ovular state, as in ordinary Ascidians, and that the kalymmocytes 
or migrating follicle cells are homologous with test cells and are really 
abortive ova. Salensky would derive Pyrosoma from the Synascidice , and 
