April 7, 1881] 



NA rURE 



543 



BIOLOGICAL NOTES 



The Shining Slave-Maker (Polyergus lucidus). — The 

 Rev. H. M'Cook is as fortunate as he is ener'/etic in hii studies 

 of the American ants. At the December 18S0, meeting of the 

 Academy of Natural Sciences of Philadelphia he read a paper 

 on the discovery at the foot of the Allcj^heny Mountains, near 

 Altoona, of a nest of Polyei's^iis lucidus, the America! represen- 

 tative of the Legionary Ant of Hu'ier (P. rii/escens), an ant 

 associated with that author's discovery of ant-nests, in which 

 certain ants have associated w ith them, in a sort of slavery, ants 

 of another species. Ttie nest had four gates separated a few 

 inches from each other ; the chambers were placed one above 

 the other, united by tubular galleries. In an inner ovoid chamber 

 numbers of the ants, male and female, appeared ; mingled with 

 thee in large nunbers were workers in three forms — major, 

 minor, and dwarf of Formica Schauffits i. A portion of the 

 excavated nest was broken iuto, and on the next day but one 

 w.ts visited. None of the shining ants were at work, but the 

 "slaves " were very busy cleaning out the galleries ; a portion of 

 the slaves were engaged in an extensive migration ; a few were 

 carrying their fellows, but for the most part the deportation was 

 confined to the males and females of the shining ants. It was 

 wonderful to see the large virgin-qjeens carried up the [jerpen- 

 dicular face of the cutting for eighteen or twenty inches, and then 

 for the distance of six feet over the ground and through the grass, 

 and this in a few seconds over a minute. The shining ants are 

 able to take a ni Jst wonderful grip. One of them had fallen 

 under the displeaure of another, who held her firmly grasped 

 by the midd'e thorax. Anxious to preserve the colony from 

 unnecessary lo-s, Mr. M'Cook lifted the two out on the point of 

 a quill toothpick, laid them on his hind, and thrust the fine 

 point of the quill bet veen the jaws of the agressor, and so teased 

 her that she released her fellow. The rescued ant instantly 

 clasped the palm of his hand, threw her abdomen under her, 

 and then, with back curved like that of an angry cat, saned and 

 tugged away at the skin until an abra-ion was made. The other 

 ant still clung fast by her mandibles only to the toothpick's point, 

 her body stretched out into space, her limbs stretched onwards, 

 except one hind leg, which was a little bent upward, aid thus 

 without any perceptible support except that which her jaws gave 

 her upon the quill-point, she hung out-tretched for several 

 minutes. About a month after its discovery the nest was again 

 visited ; it was abundantly peopled ; the winged forms of the 

 shining ant were however gone. Having succeeded in colonising 

 these ants Mr. M'Cook w-as able to confirm in many particulars 

 the statements of Huber, Forel, and others, but he never hap- 

 pened to see the slaves feeding their masters. He noticed that 

 they seemed to like to move towards both warmth and light, but 

 he does nit seem to have settled the question whether they would 

 not prefer the warmth without the light. They would appear to 

 be very clean in th;ir ways and persons. Various experiments 

 seemed to establish the fact that these slave-makers always keep 

 a guard ready at once for any attack. 



On the Red Colour of Salt Cod. — During the hot and 

 damp weather of summer in the United States the dried codfi h 

 sometimes exhibit a peculiar redness of colour. These red fish, 

 as is well known, putrefy comparat'vely quickly, and this fact, 

 taken i n connection with the disagreeable, and in such fish unusual, 

 colour, renders them unfit for market, so that in s asons when 

 the redness prevails dealers in codfish suffer often very con- 

 siderable losses. Prof. Farlow, M. 1 1., was requested by the 

 United States Fish Commission to investigate this subject, and 

 his report ap,)ears in the Fish Report for iSSo. In Sejitember, 

 1878, he went to Gloucester to examine the fish stores. The 

 weather was at that time hot and damp, and the codfish then 

 being prepared for the market were largely affected by the red- 

 ness. This redness disappears with the return of cool weather. 

 In most cases it d jes not appear until the fi,h have been landed 

 from the vessels, though in a few case^ the colour has appeared 

 in the stock while still on board. A microscopical examina- 

 tion showed that the redness was owing to a very minute plant, 

 Clathrocystis rosco-pcrsicina, a species known to be closely related 

 to C. icruginosa, so common in fresh-water ponds, and which 

 has lately come into public notice in the States in consequence of 

 the so called pig pen odour which it exhales when decaying. 

 This red species is kno \n both in America and Europe, and has 

 been recently investigated by Cohn and others. It may some- 

 times be found tinging the surface of damp ground with a 

 purplish tinge, and the anatomist is not unfamiliar with it as 



growing in his macerating tubs. It would appear not to flourish 

 or increase very rapidly at a temperature below 65° Fahr. How 

 it got to attack the dried fish was the next question. It was 

 found that the plants could come froji many sources, for it was 

 fou'id present in quantities in the wood-work of the wharves and 

 packing-stores, but above all Prof. Farlow detected it in the salt 

 with which the fish were cured. The salt from Cadiz had even 

 a slight rose tinge. It will be a matter of interest, which perhaps 

 some of our readers may help to solve, as to whether this plant 

 is known in European fish-stations. In the great Norwegian 

 cod-fisheries the temperature may not be high enough to favoiu: 

 its groAth. As re uedies Prof. Farlow suggests care in the 

 selectiijn of salt, and the constant cleaning of all wood -work or 

 vessels that may come in contact with the fish. In addition to 

 the red alga small quantities of cells destitute of colouring- 

 matter and arranged in fours were not unfrequently found in the 

 infected cod-fish. These ^ugge^ted the genus .Sarcina, but were 

 not S, -■eiitricuH. They rather, except in the absence of col air- 

 ing-matter, resembled Clccocapsa crcpidmum, Thuret, which 

 species is common enough on the wood-work of the Gloucester 

 wharves. While there is this resemblance Prof. Farlow prefers 

 for the moment, and pending further investigation, to call it a 

 Sarcina, and to describe it as a new species (S. ? morrhun) . 



M.A.RINE ISOPODS OF NEW ENGLAND. — One of the most 

 remar'.;able papers forming the extensive series of appendices 

 to the Report of the United States Commissioners of Fish and 

 Fisheries for 187S is perhaps that by O-car Harger on the 

 marine Isopod. of New England and adjacent waters. The 

 limits clMsen commence at Nova Scotia to the north and extend 

 southwanls to New Jersey. Forty-six species are recorded, and 

 figiu'e^ of the^e with the requisite details of anatomy are given 

 on thirteen plate. ; several new species and one new genus 

 (Syscenus) are described. It will be noted that the number of 

 species is very con-iderably less than that kno.vn tti frequent the 

 British coasts, antl of the former only eight are identical with 

 British forms. This difference is very marked in the genus 

 Sphssroma, of which genus there is but oae species native to 

 New England, while Bate and Westwood describe a dozen 

 species belonging to this family as natives of Britain. Limnoria 

 Hgnosiim, one of the most destructive of the group, is appa- 

 rently as common on the American coasts as on our own 

 shores. It d )es not usually occur much below high-water mark, 

 though Prof. VerriU has found it at a depth of ten fathoms in 

 Casco Bay, and it was dredged by the U.S. Fish Commission 

 at a depth of 74 fathoms in Cape Cod Bay, Massachusetts. 

 Of the family of the Cymothoidoe, of which we believe as yet no 

 species has been found around the British Islands, three species 

 belonging to three different genera are in Mr. Harger's list. — To 

 this memoir there is appended a very complete list of authorities 

 and an alphabetical index. 



Statistics of Disease in Italv. — In a recent paper to the 

 Lombard Institute, Prof. Sangalli gives statistics of the diseases 

 which terminated fatally in the Civic Hospital of Pavia during the 

 period 1S55 to 1881. The material was 6644 bodies which 

 came up for autopsy, and the causes of death were, in de- 

 creasing order, genuine inflammation, 4504 deaths ; tuberculosis, 

 80S ; pyaemia, 337 ; cancer, 366; hepatic cirrhosis, 252 ; extra- 

 vasation of blood in the brain, 254 ; chronic ulcer (gastric and 

 duodenal), 72, &c. (there being 2140 deaths apart from those by 

 true inflammation). The 4504 deaths from inflammation pre- 

 sented 7962 separite inflammations. The deaths from tubercu- 

 losis are seen to be about 12 per cent. The ages most exposed 

 to that di-ease lie between 20 and 30 ; next come those between 10 

 and 20, and between 30 and 40, about equal. There were twelve 

 cases between 70 and 80, and one in an old man of 84. It does not 

 appear that one sex suffers m ire than the other. Cancer occurs 

 most between 50 and 60, and most largely in liver, lymphatic 

 glands, and stomach. The patients were largely of the peasant 

 class, and the author cannot support Niemeyer's view, that 

 people living in marshy districts, liable to malaria, have a 

 certain immunity from tuberculosis. Nor do the figure^ confirm 

 the asserted tendency of ulcer in the stomach to favour the 

 development of tuberculosis. Pyaemia appeared mostly in the 

 lungs (149 cases out of 470), pleura, 99; liver, 73, &c. In 

 some years there was a remarkable diminution of this disorder. 



The Eve and Intensity of Colour. — With an apparatus 

 consisting of two Nicols with a gypsum plate between, and a 

 spectroscope with a third Nicol attached to the eye-piece, Herr 

 Dobrowolsky has examined the sensibility of the eye to spectral 



