104 



HARD WICKE } S S CIE NCE - G OS SIP. 



blush red, the spots being distributed so scantily as 

 to give it a slight resemblance to a Sparrowhawk's 

 egg. Other varieties have a zone of a darker hue 

 encircling either ends. I have at times seen eggs of 

 this bird of a light yellowish-brown, with spots so few 

 and minute as to resemble a strongly-marked speci- 

 men of the Red-legged Partridge (Perdrix rubra). 

 1 1 is a well-established fact that there is generally one 

 egg in the "clutch" much smaller than the others. 

 This, however, may be explained by its being the last 

 egg, and the producing organs in the female having 

 been weakened by previous exertions. In due time 

 the eggs are hatched, and on the appearance of the 

 young, the energy and watchfulness displayed by the 

 parent birds are extreme. Generally they are both to 

 be found in the vicinity of their young, and are never 

 absent together, one (probably the female) being 

 continually with the young, attending to their re- 

 quirements, and rigorously guarding them from all 

 intruders ; while the other parent is occupied in pro- 

 curing food, of which there is always an abundant 

 supply. Their only real enemy, and of whom they 

 have most fear, is man. Should a person invade the 

 precincts of their territory, and threaten their precious 

 "citadel," the vigilant guards always give the invader 

 due warning by uttering a shrill, piercing cry. Should 

 the hard-hearted fellow take no heed of this, but be 

 intent on robbing the nest of its young occupants, the 

 parents, on the too near approach of the robber, fly 

 up from their resting-place and. sail around, out of 

 immediate reach of danger, uttering the while a 

 shrill, plaintive note. Sometimes either of them will 

 make a swift descent at the intruder's head, it would 

 seem, but, checking its course, will sweep rapidly past 

 at a short distance overhead, making a loud rushing 

 noise. 



The eggs of this neat-looking hawk stand at the head 

 of the schoolboy's collection. When he is in possession 

 of one, he is satisfied, and congratulates himself on his 

 " luck," and on hearing of any one of his schoolmates 

 having a rival collection he immediately sets out to 

 view it. The first question asked by him is, " Have 

 you a Kestrel's egg?" If the answer be in the 

 negative, he thinks absolutely nothing of the col- 

 lection, — in fact, treats it with contempt, tells the 

 owner of it about his Kestrel, how and where the 

 egg was procured, and finally departs, thinking he 

 has made an impression on his brother collector. 



The Kestrels, both male and female, are very 

 assiduous in their attention towards their offspring, 

 keeping them sufficiently supplied with nourishment. 

 Space will not allow of me to describe the birds, but 

 they are so well known that it is almost unnecessary. 



The "Veteran Eel."— Replying to J. J. New- 

 ton ; the veteran eel, when I bought him in London, 

 was not quite three inches long, and at his death he 

 was eighteen inches long, so that he grew fifteen 

 inches in twenty-two years. — Ben Plant. 



WHAT A DIATOM IS.* 

 By Mons. Julien Deby, 



Vice-Vresident of the Belgian Microscopical Society. 



(Translated by F. Kitton, Hon. F.R.M.S., Corresponding 

 Member de la Socie'te Beige de Microscopic) 



BY the kind permission of M. Deby I am enabled 

 to place before the readers of SCIENCE-GOSSIP 

 a translation of a very interesting paper on the above 

 subject, read by M. Deby before the Microscopical 

 Society of Belgium. The attention of foreign dia- 

 tomists has lately been directed to the elucidation 

 of the life history of these remarkable organisms, in 

 some instances with the hope of constructing a 

 natural system of classification. Herr Pfitzer, of 

 Bonn, and Mons. Petit, of Paris, have both published 

 treatises on this subject. f 



Fig. 71. Ideal section of a navicula : A, nucleus and nucleolus ; 

 B B, protoplasm ; b' b', primordial utricle ; c c, endochrome ; 

 E E, oil globules ; F f', valves ; g G g' g', connectives ; D D, 

 central cavities. 





c 



Fig. 72. Section of a diatom commencing deduplication: a, 

 nucleus commencing to divide, with two distinct nucleoli ; B, 

 protoplasm ; b', primordial utricle ; c, endochrome ; D, cen- 

 tral cavities ; F f', valves ; G c/, connectives. 



Mons. Deby's little treatise is devoted to a descrip- 

 tion of the living diatom and its mode of growth. 

 Of all the forms of unicellular plants, the diatom is 

 probably the most remarkable, not only on account 

 of its siliceous shell, but also for its mode of repro- 

 duction. — F. K. 



* "Ceque c'est qu'un Diatome'e?" par Julien Deby, Vice- 

 Prc-ident de la Societe Beige de Microscopic Extrait dcs 

 Bulletins de la Societe Beige des Microscopie pour 1877. 



t " Untersuchungen uber Bau und Entwicklungen der Bacil- 

 lariaceen," von Dr. E. Pfitzer. 



" Un Essai de Classification des Diatome'es," par Paul Petit. 



