Pseudomonas tolaasii. [Descriptions of Fungi and Bacteria].

A description is provided for Pseudomonas tolaasii. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Agaricus bisporus, A. bitorquis, A. arvensis, A. campestris, edible mushrooms. Also reported to cause losses on Pleurotus eryugii and P. ostreatus (65, 1655). DISEASE: Bacterial blotch of cultivated mushrooms. Spots of a pale yellow colour arise on the caps as they expand. These enlarge and become dark brown, often wet and sunken, and may coalesce. Stalks are also frequently attacked. The infection does not penetrate deeply, but renders the mushroom unsaleable. GEOGRAPHICAL DISTRIBUTION: Reported from China (62, 2744), India (57, 2373), Israel (60, 4791) Taiwan (59, 3507), Australia (NSW, Qd, Tas., Vict., 63, 3168), New Zealand (culture in PDDCC), Denmark, France (30: 554), Italy (50, 3375), Netherlands (37: 66), Rumania (42: 359), UK, USA (MD 37: 66, ME 64, 1386, MN, MO, PA 60, 2315). Probably much more widespread than these records suggest. TRANSMISSION: On one farm studied in England the primary sources of infection were the peat and limestone used in the casing process. One percent and two percent of samples respectively yielded the bacterium, which was apparently present as a normal constituent of the associated micro-flora. Water, soil spawn and spawned compost were all found to be free of infestation (Wong & Preece, 1980). Under the right conditions these low numbers are able to increase sufficiently to cause serious disease in beds. Agents of secondary spread within an infested farm are many and complex. Wong & Preece were able to isolate the pathogen from workers' hands, clothing, baskets, ladders, knives, and from cropping house floors. The organism was also trapped from the air inside and just outside infested houses, and in low numbers near the bed surfaces of apparently healthy houses. Spores discharged from diseased mushrooms seemed seldom to carry bacteria, but sciarid flies (Lycorilla sp.) and mites (Tyrophagus sp.) are able to carry infection.

Palladium arsenide-antimonides from habira, Minas Gerais, Brazil

SummaryThe arsenopalladinite concentrates from Itabira, Minas Gerais, Brazil, have been found to contain three arsenide-antimonides of palladium, namely arsenopalladinite, atheneïte, and isomertieite. The second and third of these are new minerals.Arsenopalladinite, redefined, is Pd5(As,Sb)2 and triclinic with a 7·399, b 14·063, c 7·352 Å, α 92° 03′, β 118° 57′, γ 95° 54′. Z = 6. Dmeas = 10·4, Dcalc = 10sd46. In reflected light arsenopalladinite is white with a yellowish creamy hue. The mineral shows complex polysynthetic twinning and is strongly anisotropic. Reflectance measurements at 470, 546, 589, and 650 nm respectively gave: in air, 46·67–48·86, 49·97–52·90, 52·82–54·96, and 55·61–57·72 in oil, 32·30–35·07, 37·12–39·40, 38·97–41·32, and 40·28–43·07. VHN100 379–449, av. 407.Atheneïte, (Pd, Hg)3As, is hexagonal, space group P6/mmm and cell dimensions a 6·798, c 3·483 Å. The strongest lines of the powder pattern are 2·423 vvs (111) , 2·246 vs (201), 1·371 s (212), 1·302 s (302), 1·259 s (321). Z =2. Dcalc = 10·16. In reflected light atheneïte is white with a faint bluish tint compared to arsenopalladinite. Anisotropy distinct. Untwinned. Reflectivities for the two grains examined are: in air, 470 nm 47·51–54·75, 47·43–51·18; 546 nm 50·79–58·01, 51·36–54·36; 589 nm 53·13–61·01, 53·24–55·86; 650 nm 55·94–63·13, 54·76–56·77; in oil, 470 nm 30·03–43·67, 33·46–37·31; 546 nm 33·42–47·75, 37·64–41·07; 589 nm 35·80–49·04, 39·40–42·24; 650 nm 38·25–50·49, 41·07–42·85. VHN100 419–442, av. 431.Isomertieite, (Pd,Cu)5(Sb,As)2, is cubic, space group Fd3m, a 12·283 Å. The strongest lines of the powder pattern are 2·356 vs (333, 511), 2·167 vvs (440), 0·8599 s (10.10.2, 14.2.2), 0·8206 s (12.8.4), 0·7996 s (10.10.6, 14.6.2), 0·7881 s (999, 1.11.1, 13·7·5, 15·3·3), 0·7801 s (12.10.2, 14.6.4). Z = 16. Dcalc = 10·33. In reflected light isomertieite is a pale yellow colour. One grain was isotropic, three others displayed weak anisotropy. Untwinned. Reflectance measurements at 470, 546, 589, and 650 nm gave respectively: in air, 44·74–46·46, 52·23–53·25, 55·05-57·49, 56·97–62·03; in oil, 31·04–31·40, 38·42–38·90, 40·80–42·16, and 42·91–45·63. VHN100 587–597, av. 592.Quantitative colour values are also given, and the chemical and optical properties are compared with the related mineral, stibiopalladinite.

TRICHOGRAMMA PRETIOSA, RILEY: COLOUR VARIATION IN THE ADULT, WITH DESCRIPTION OF A NEW VARIETY

In the original description of this insect, * Dr.Riley says that on account of its uniform pale yellow colour it is easily distinguished from Trichogramma minutum, Riley, which is black. Unfortunately, this does not hold.† Out of the hundreds of specimens of pretiosa reared during the enire season of 1904, at Paris, Texas, from the eggs of Heliothis obsoleta, Fabricius, there appeared from a lot of host eggs on Sept. 20th a number of dark individuals, which could easily have been mistaken for a distinct species.

NEW NORTH AMERICAN HOMOPTERA.—NO. VII

1. Idiocerus Amœmus, n. sp.Allied to I. suturalis, but smaller. Female of a uniform pale yellow colour, pronotum and scutellum tin gedwith fulvous or ferruginous, the former with a spot behind the inner angle of each eye and a median vitta, pale. Mesonotum with a black band bordering the scutellum, at least posteriorly; extreme tip of scutellum yellow. Elytra hyaline very slightly tinged with fulvous, becoming smoky toward the apex; nervures pale yellow. Wings hyaline, highly iridescent. Eyes rufous. Oviduct ferruginous.

II. Chemical examination of the fluid from the peritoneal cavity of the nematode entozoa

Some time ago Dr. Cobbold sent me a quantity of fluid which he had extracted from about seventy perfectly fresh specimens of the Ascaris megalocephala of the horse, and he requested me to make an analysis of it. I most willingly availed myself of this unusual opportunity of ascertaining the composition of this fluid, the sample procured by Dr. Cobbold being fortunately large enough for the purpose. The analysis of this fluid is interesting as showing that its composition is similar to that of juice of flesh in the higher animals, and consequently that the process of assimilation occurs in these worms much in the same way as in those animals where the organs of digestion and circulation are perfectly developed. It also shows that a fluid similar to that existing in muscular tissue is apparently elaborated by the intestines of the Ascarides , while in the higher animals this fluid is formed from the blood. The fluid was turbid, of a pale yellow colour, and emitted an offensive odour, although not of decomposition.

IX. On the constitution of the resins

The object of the investigation, of which the present paper forms a part, is 1. To determine the relative composition of the various resins which occur in nature. Possessing so many properties in common, this large family of natural productions ought also to present many analogies in constitution. 2. To ascertain how far they may be considered as derivatives from one common radical; and 3. Whether it is possible to represent them all by one or more general formulæ. I. Resin of Mastic. Mastic resin is said to be obtained from the Pistacea lentiscus , and to be produced chiefly in the island of Chios. It occurs in drops or tears, which are transparent, and of a pale yellow colour. It melts at 212°, and emits a peculiar and not unpleasant odour. Fused in a retort it gives off an acid liquid in small quantity. If the heat be raised to 300° Fahr. and upwards, the melted mass froths up, and water and acid vapours are evolved. At a higher temperature a pale yellow liquid distils over very slowly, at first of the consistence of oil, but increasing in thickness as the process proceeds, water and acid being also given off during the whole process. What remains in the retort is of a black colour, and nearly insoluble in alcohol.