264 
POPULAE SCIENCE EEVIEW. 
Is alleged that Professor Leuckart has discovered several supplementary eyes 
in a fish. The Professor states that the brilliant spots grouped with more or 
less regularity upon certain fish of the group Scopelinidce, are really accessory 
eyes. The existence of more than a thousand such eyes in a vertebrate 
animal is quite unexpected. They are distributed over the hyoid apparatus, 
and on the head and belly, where they form two rows, which are parallel. 
Herr Leuckart bases his opinion upon the anatomical structure of the organs 
known as spots, these having really the form of little cylinders, the anterior 
part of which is occupied by a spherical body like a crystalline lens, behind 
which is a sort of vitreous humour. 
The Muscular Fibres of the Heart of Vertebrates. — We have received 
from Dr. J. B. Pettigrew, the accomplished sub-curator of the Royal 
College of Surgeons’ Museum, a copy of his excellent monograph on the 
above subject. The memoir is certainly the finest which has yet been 
produced ; for it is comprehensive, clear, and accurate, and is accompanied 
by a great number of beautiful lithographs, which have been taken from 
photographs of actual dissections. The arrangement of the muscular fibres, 
as demonstrated by the author, shed much light upon the peculiar movements 
of the heart. For this reason the essay has a great physiological importance, 
and, from the circumstance that the anatomy of the heart in the four 
vertebrate classes is fully explored by Dr. Pettigrew, it is of equal import 
and interest to the comparative anatomist. We have also received Dr. Petti- 
grew’s paper on the valvular apparatus of the circulatory system, and 
we commend it likewise to our readers’ favourable notice. 
The Natural History Review. — We regret to observe that the Natural 
History Review has ceased to exist. This journal, which was originally an 
Irish periodical, and subsequently an English one, was, without exception, 
the most excellent periodical of its kind. We fancy its articles were of too 
high a standard to secure for it a large number of subscribers, and hence its 
failure as a commercial undertaking. 
The Ailanthus Silk-worm. — Those who think that this caterpillar cannot 
be successfully cultivated in this country should read the subjoined letter, 
which was recently addressed to the Times : — “ Sir, — Having seen a letter in 
the Times relating to the new oak silk-worms, Bornbyx Yama-mai, and their 
probable acclimatization in England, may I be allowed to say a few words ? 
I have cultivated them for two years with the greatest care, and from my 
observations fear they will never stand our changeable climate. I reared 
them successfully, both under glass and in the open air, till the fourth 
change of skin, when they all died of the malady called 1 pebrine,’ induced 
by a few days of rainy and cold weather in the month of June. The 
Ailanthus worm, on the contrary, is perfectly hardy, fearing no rain or wind, 
or even a slight frost. His only enemies are in infancy the ants ; in old age, 
the tom-tits. I rear many thousands every year without the slightest 
difficulty, and shall be glad to give any persons the benefit of my experience. 
To show they are gaining much in the public estimation, since I intro- 
duced them into England three years ago, I have sold and given away 
70,000 eggs annually, besides sending cocoons to all parts of the world ; and, 
more than that, I have a gown made from the silk. 
“ Dangstein, Petersfield, Feb. 24. 
Dorothy Nevill.’ 
