ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
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a duct which, is so short and wide as hardly to deserve the name duct. 
There is no histological distinction between funnel, duct, and brain. 
Later on, the duct becomes a small round tube, and the brain becomes 
much flattened dorsoventrally. Canals for a short time ramify through 
the tissue of the brain, but the tissue soon becomes solid. There is 
evidence that the early function of the ciliated funnel and its duct is 
the aeration of the brain, while the waste products of the brain-cells 
may have been passed away by them. The later condition of the 
ciliated funnel indicates that it is very probably a sense organ which 
serves to test the quality of the water entering the pharynx. 
Periodic Regeneration of Upper Half of Body in Dipiosomidse.* — 
Mr. A. Oka states that there is a new species of Diplosoma , found on 
the Japanese coast, in which the upper half of the body is periodically 
renewed ; the species, which may be called D. Mitsukurii , is most 
nearly allied to D. chamseleon. When the separate members of a 
colony are examined, each is seen to possess two branchial sacs, and 
two peribranchial sacs of different ages. In short, the whole upper 
half of each individual is double. In stained sections it is clear 
that the older half has begun to degenerate. In some cases the 
oesophagus is trifid, and in this case one branch extends to the outer 
layer of the ectoderm, and ends blindly, while the branchial sac has 
completely disappeared. The younger half-individual is usually bent 
to one side, and only gradually takes on an upright position, while the 
older becomes crumpled up and finally obliterated, even the scar formed 
by it on the ectoderm disappearing. From a lateral bud a third half 
individual is soon developed, which goes through the history of the 
second, which follows the fate of the first. 
Dolchinia mirabilis.j — Under this name Prof. A. de Korotneff 
describes a remarkable new Tunicate from Naples; it is allied to 
Anchinia and Doliolum. There is a colonial tube to which the zooids 
are loosely attached ; they are arranged pretty regularly ; on either side 
of the groove which extends along the upper part of the tube there lie the 
youngest zooids, and the size of these increases with their distance from 
the groove. The lower surface of the tube has no zooids. With regard 
to budding it is suggested that the following may be the phylogenetic 
series — (1) Buds arising from the proliferous stolon produce a nurse 
only which cares for the sexual form — Dolchinia. (2) Buds produce two 
different nurses, one of the colony (lateral form) and one of the sexual 
form — Doliolum. (3) Buds produce two different nurses, but the sexual 
form, or, rather, its germ does not become planted on its nurse, but fixes 
itself directly on the colonial tube, the other form is rudimentary 
Anchinia. (4) Buds produce only a nurse which cares for the colonial or 
lateral form, and there is no sexual nurse — Hypothetical form. A more 
extreme reduction would be a simple alternation of generations, asexual 
and sexual, with an abolition of the sterile form. The asexual form of 
Dolchinia is not known, but we may suppose that it has a proliferating 
stolon, and a tail like Doliolum ; it is probably of large size and has a 
heavy and very long tail. 
* Biol. Centralbl.. xii. (1892) pp. 265-8 (1 fig.). 
f Mittheil. Zool. Stat. Neapel, x. (1891) pp. 189-205 (2 pis). 
2 K 2 
