302 



SCIENCE-GOSSIP. 



with the object of studying marine painting that 

 he went to Heligoland about the year 1836 ; but he 

 had not long been on the island before he con- 

 tracted an acquaintanceship which led to his 

 marrying and making it his home for the remainder 

 of his life. 



The keen interest in ornithology, which was 

 afterwards to make him famous, appears to have 

 developed itself not long after his arrival on the 

 island. It quickly led to his beginning to form a 

 collection of the stuffed skins of such birds as came 

 in his way, and also to his commencing the journal 

 of observations which he kept with such unfailing 

 regularity throughout the rest of his long life. It 

 was not until Gatke was forty years of age that 

 the good use to which he had put his residence 

 upon the remarkable islet first became known to 

 European ornithologists. From this time onward 

 Gatke and Heligoland became more and more 

 familiar to ornithologists, and at the same time 

 more and more inseparable. Gatke himself 

 abated nothing of his self-imposed labours, 

 ultimately rendering his system so perfect that 

 the majority of the islanders were gradually 

 pressed sufficiently into the service of the cause to 

 be able to prove valuable allies in making observa- 

 tions for him. 



In process of time Gatke began to filter out a 

 portion of his vast store of information to the 

 appreciative circle of British ornithologists. This 

 he did chiefly through the medium of " The Ibis," 

 and also in the shape of gratuitous data supplied 

 to several of the ornithologists who visited the 

 island. It was not, however, until the veteran 

 observer was in his eightieth year that the whole 

 of his observations and deductions were placed 

 before the world in his " Die Vogelwarte 

 Helgoland," printed at first in German, but after- 

 wards rendered accessible to our countrymen in 

 the English edition of 1895. Upon the contents of 

 this volume it is unnecessary to dwell in this place, 

 as its value has been and will for years to come be 

 almost universally recognized, in spite of whatever 

 objections may be advanced against some of the 

 opinions adduced by its author. 



The island of Heligoland itself may be described 

 roughly as a triangular tableland, surrounded by 

 nearly perpendicular cliffs, the almost level surface 

 having a total area of only about one- fifth of a 

 square mile. It is situated about forty miles from 

 the mouth of the Elbe. The total number of species 

 of birds enumerated by Gatke as having occurred 

 on this " speck in the ocean " is 396, but one of 

 this number {Geocichla dauma) was given in error 

 (see " Ibis," 1894, p. 298), while some few others are 

 recorded as having been seen only. On the other 

 hand, at least one species has been added since the 

 publication of Gatke's work, 



10, Harrington Street, London, N,W. 



A NEW MEALY-BUG. 



(Dactvlopius pseudonip^.) 

 By T. D. a. Cockerell. 



T N the January number of Science-Gossip I 

 gave a description by Mr. Pergande of a 

 mealy-bug found in a Michigan hothouse, believed 

 to be Dactylopius nipce, of Maskell. Mr. Pergande 

 himself had all along inclined to the opinion that 

 it was a distinct species, though unwilling to 

 publish it under a new name. I had been con- 

 vinced that it represented only a variety, but since 

 then I have studied some specimens found on the 

 leaves of a palm in a Californian greenhouse, sent 

 to me by Mr. Ale.x. Craw, and am converted to the 

 opinion that it is a distinct though closely related 

 species. In addition to the difference in the 

 antennae, the new species {D. pseudo7tipa) differs 

 also in the colour of the male and larva, D. nipce 

 having, according to Maskell, a brownish-red male 

 and a purplish-red larva. The following description 

 is from the Californian material : 



Dactylopius pseudgnip.-e, n. sp. 



Female about two millimetres long, oval, bright 

 crimson, covered with dense yellowish-white meal, 

 which tends to elevate itself into four rows of 

 dorsal protuberances. Sides with dense mealy 

 tassels, pointing backwards. The female boiled in 

 caustic alkali, stains the liquid claret colour ; the 

 contents of the body give a further reddish-brown 

 stain, but cleared individuals are light violet. Anal 

 ring with the usual six hairs, which are stout- 

 Caudal tubercles quite pronounced for a Dactylopius, 

 with the usual two conical spines, short hairs, and 

 longer caudal bristle, which is not longer than and 

 not quite so stout as a hair of the anal ring. Legs 

 ordinary, femur tolerably slender, tarsus about two- 

 thirds length of tibia, each with a few bristles only. 

 Digitules slender, with distinct knobs ; tarsal 

 digitules not very long. Antennae 7-jointed, formula 

 7241(63)5. 



Newly-hatched larva pale lemon yellow. 



Male sac ordinary, but pure white, not yellowish 

 like the female. Male light yellow. 



Mesilla, New Mexico, U.S.A.; 

 March yth, 1897. 



Experimental Farms. — Professor Saunders, 

 LL.D.,F.R.S.C.,F.LS., etc. .Director of the Experi- 

 mental Farms of the Dominion of Canada, gives 

 his annual report of "The Results Obtained in 1896 

 from Trial Plots of Grain, Fodder-Corn and 

 Roots." It is one of an admirable series upon the 

 technical work so ably carried out under the direc- 

 tion of Professor Saunders at the various experi- 

 mental farms under his management in the Dominion 

 of Canada. The marked success of the investigation 

 into the varieties of economic plants suited to the 

 great climatic range existing in Canada, which has 

 been carried out at these establishments, has amply 

 justified the annual votes which the Dominion 

 Parliament has passed tor that purpose. 



