SCIENTIFIC SUMMARY. 
377 
perfect Englyphce. Gruber attaches much importance to the fact that'the 
separate portion grows into a complete animal before the original nucleus 
begins to divide, and regards this as furnishing further evidence of the cor- 
rectness of Strasburger’s opinion that the true seat of activity in cell- 
formation is not the nucleus but the protoplasm, — at any rate, as Gruber 
points out, his observations furnish a fresh proof that the nucleus of the 
Rliizopod is a typical cell-nucleus. He has since observed a similar process 
of division in the nearly allied genus Cyphoderia. 
A New Species of Horse. — The Annals and Magazine of Natural History 
for July contains a translation of a Russian paper, in which M. Poliakof 
brings forward a mass of evidence in proof of the existence of a hitherto 
unknown species of horse, not far from Zaisan, in Central Asia. The animal 
appears to resemble a small domestic horse, of a dun colour ; its head is 
large in proportion to the size of the animal ; and the root of its tail is 
destitute of long hairs for some distance. M. Poliakof names his supposed 
new species JEquus Przewalshii , in honour of the traveller who brought the 
skin to Russia. He regards it as a true horse, and remarks that 1 if it were 
possible to prove that culture influenced the growth of the tail, and that this 
became more hairy, and the mane longer, under altered conditions of life,’ it 
might be affirmed that ‘it was indeed the animal whose ancestors were 
reclaimed by man in the stone period, the so-called domestic horse of our 
day.’ 
Deep-sea Pycnogonidce . — The 1 Sea Spiders/ dredged by the U. S. steamer 
Hlake , during the summer of 1880, along the east coast of the United 
States, have been described by Mr. E. B. Wilson in the Bulletin of the Museum 
of Comparative Zoology. The deep-sea forms here, as elsewhere, are remark- 
able for their colossal size, compared with those of shallower water, and iu 
a number of forms the eyes ( ocelli ) are either rudimentary and destitute of 
pigment, or altogether absent; while, on the other hand, in one genus, 
Pallenopsis, the eyes are unusually large. Mr. Wilson specially describes 
the morphology and innervation of the anterior appendages ; upon which he 
remarks that * it is easily possible that the external resemblance of a Pycno- 
gonid to an Arachnid are those of analogy only, and have no morphological 
significance.’ This is the more probable from the extreme variability of the 
three anterior pairs of appendages in position and structure. — Amer. Nat., 
August, 1881. 
