SUMMARYA serological analysis of the extracellular antigens of Micropolyspora faeni by immunodiffusion with a combination of sera revealed 29 individual antigens. A survey was made of the incidence of precipitins to the antigens in sera from patients with clinical farmer's lung disease (FLD) and other respiratory diseases.Precipitating antibody was found in 75 % of farmer's lung cases and in 20 % of other cases who had been exposed to the same environment. More precipitin reactions were seen in sera from severe forms of FLD than from milder forms. The distribution of precipitins to individual antigens was not significantly affected by severity of disease.Most of the patients with precipitins to M. faeni, but without the symptoms of FLD, were suffering from mild or moderate symptoms of other respiratory diseases with a history of chronic onset of symptoms. The distribution of precipitins to individual antigens in this group was similar to that in clinical FLD patients but the incidence was considerably lower.The significance of these results is discussed.

, but its diagnosis presents difficulties. Even when infection is established, blood cultures may fail to yield candida. When, on the other hand, the diagnosis is in doubt, the isolation of Candida species may be of little significance without other evidence of infection, because of the frequency with which these organisms are found in mucocutaneous situations (Mackenzie, 196 1 ; Marples, 1966) from which they may contaminate specimens. Clearly a reliable serological test would be of great value. Winner (1955) concluded from a study of over 2500 subjects that a high agglutination titre was of little or no diagnostic significance in a case of suspected candida infection. However, Stallybrass (1 964) and Taschdjian et al. (1 964a and b; 1967) have produced evidence that precipitins to somatic antigens of Candida species seldom appear in the absence of infection. Our observations made on patients undergoing open-heart surgery suggest that the finding of high levels of precipitins to candida may be indicative either of candida endocarditis or inapparent candida infection. METHODS Sera We have examined 409 sera for the presence of agglutinins and precipitins to Candida albicans, C. tropicalis, C. guilliermondii and C. parapsilosis. The study began when, between Nov. 1965 and May 1966, sera were received from four patients (M.B., C.B., J.C. and R.H.) in whom a clinical diagnosis of candida endocarditis had been made. When precipitins to Candidiz species were detected in them, the study was extended to another 64 patients who underwent open-heart surgery between June 1966 and Sept. 1967; two of these patients (D.S. and J.R.) developed candida endocarditis. As far as possible blood was taken immediately before operation and thereafter at weekly intervals. Agglutination and gel diffusion precipitin tests were carried out on all sera. Agglutination tests Candida species were grown on glucose peptone agar for 48 hr at 37"C, washed off with isotonic saline and made into stock suspensions of approximately 50 per cent. packed-cell volume, which Agglutination tests were carried out with suspensions of whole yeast cells.

Ten metabolites, hydrocotoin (2-hydroxy-4,6-dimethoxybenzophenone), 2,3'-dihydroxy-4,6-dimethoxybenzophenone, 1,3,5-tri hydroxyxanthone, 4',5'-dihydro-I ,6,7-trihydroxy-4',4',5'-trimethylfurano (2',3' : 3,4)xanthone, volkensiflavone, morelloflavone ; and from methylation of the crude extracts, 1.7-dimethoxyxanthone, 1 -hydroxy-5-methoxyxanthone, 1 -hydroxy-3.7-dimethoxy-2-(3.3-dimethylallyl)xanthone, and 1,3,6,7-tetramethoxyxanthone have been isolated from the heartwood of Allanblackia floribunda Oliver. The biogenetic significarlce of the co-occurrence of these compounds is discussed and syntheses of hydrocotoin, methylhydrocotoin, and 2,3',4,6-tetra m et h oxy be nzo p h e none are desc r i bed.As part of our studies of the plant family Guttiferae, we have examined the phenolic constituents of Allarlzblackia jlo&wzzda Oliver (subfamily Clusioideae.) A heartwood sample from Nigeria was reduced to shavings and extracted with chloroform and with acetone : both extracts produced a green colour with ferric chloride indicating cm.-l) and the mass spectrum [M+ 258, C,,H,,O,, with major fragment ions at m/e 77 and 105 (corresponding to C6H5+ and C6H,CO+) arising from cleavage either side of a carbonyl function] 2 suggested a benzophenone with one ring unsubstituted.Analysis of the n.m.r. spectrum (Table 1) enabled the HEARTWOOD acetone extract chloroform extract .+ SOLID (G)

No abstract

No abstract