Histological studies on the effects of benzoylprop ethyl and flamprop methyl on growth and development of wild oats*

Wild oats were trealed with benzoylprop eihyl and flamprop methyl alone or in combination with other herbicides and the effects on plant growth studied using histological techniques, Benzoylprop ethyl caused severe reductions in the growth of both the leaves and internodes of treated plants, Evidence was obtained which indieaies that cell division as well as cell elongalion was inhibited. The effects of flamprop methyl on plant growth were similar lo those observed for benzoylprop ethyl. Both compounds interfered with normal differentiation of vascular tissues which could account for retarded development of the higher internodes and shoot apex of treated plants. Of the various herbicides applied in combination with the wild oat herbicides, 2,4—D was more antagonistic than MCPA. while bromoxynil was the least antagonistic. Plants treated with benzoylprop ethyl plus 2.4—D had increased cell, leaf and internode lengths compared to plants treated with benzoylprop ethyl alone. Reductions in cell and internode lengths of plants treated with the herbicide combinations were not always proportional lo dry weight reductions.     

Further studies on the morphology and isolation of feline mycoplasmas

The colonial characteristics of Mycoplasma felis and M. gatae are described and illustrated. It is suggested that these characteristics may be used as a method of identification for these two feline mycoplasmas. An assessment is made of the efficacy of recovering mycoplasmas from the throats of cats using both solid and liquid media. The importance is emphasized of using liquid media when attempting to isolate mycoplasma from animals or their tissue.
Résumé. Les caractéristiques de Mycoplasme felis et M. gatae inhérentes è la colonie sont décrites et illustrées. On suggère l'utilisation de ces caractéristiques comme moyen d'identification de ces deux mycoplasmes félins. On examine dans yuelle mesure le prkélèvement des mycoplasmes de la gorge des chats au moyen d'agents tant solides que liyuides s'avère efficace d'utiliser. On souligne l'importance des agents liquides pour isoler le mycoplasme des animaux ou de leur tissu.
Zusammenfassung. Die Kolonieeigenschaften von Mycoplasma felis und M. gatae werden beschrieben und illustriert. Es wird vorgeschlagen, diese Eigenschaften zur Identifizierung dieser beiden Katzenmycoplasmen zu verwenden. Die Wirksamkeit der Methode, Mycoplasmen aus dem Schlund von Katzen mittelsfester und flüssiger Medien zu entnehrnen, wird einer Bewertung unterzogen. Rei dem Versuch, Mycoplasmen aus Tieren oder ihren Geweben zu isolieren, ist die Verwendung flüssiger Medien wichtig.     

State of dynamic equilibrium in protein of mammalian cells

Labeled strain L cells in suspension tissue culture showed no degradation of protein when maintained in logarithmic growth. Although the protein of these cells was not in dynamic equilibrium, the conclusions cannot be transferred to the intact mammalian organism.     

The cultural and pathological examination of bulls serologically positive for brucellosis

The genitalia from 34 bulls were examined for the presence of Brucella lesions using histological, bacteriological and serological methods. Tissue fluids extracted from the various genital organs and the serums were examined using the serum agglutination test (SAT), the Rose Bengal plate agglutination test (RBPT), the complement fixation test (CFT) and the indirect haemagglutination test (IHLT) for the presence of Brucella antibody. Titres to one or more of these tests were found in 17 bulls and B. abortus was cultured from 5 of these. The testing of tissue fluids from genital organs did not increase the number of serologically positive animals.     

So much for the city: Urban–rural song variation in a widespread Asiatic songbird

Song plays a fundamental role in intraspecific communication in songbirds. The temporal and structural components of songs can vary in different habitats. These include urban habitats where anthropogenic sounds and alteration of habitat structure can significantly affect songbird vocal behavior. Urban–rural variations in song complexity, song length and syllable rate are not fully understood. In this study, using the oriental magpie‐robin (Copsychus saularis) as a model, we investigated urban–rural variation in song complexity, song length, syllable rate, syllable length and inter‐syllable interval. Comparing urban and rural songs from 7 countries across its natural Asiatic range (Bangladesh, India, Malaysia, Nepal, Singapore, Sri Lanka and Thailand), we found no significant differences in oriental magpie‐robin song complexity. However, we found significant differences in temporal song variables between urban and rural sites. Longer songs and inter‐syllable intervals in addition to slower syllable rates within urban sites contributed the most to this variance. This indicates that the urban environment may have driven production of longer and slower songs to maximize efficient transmission of important song information in urban habitats.     

A NEW TECHNIQUE FOR THE ACCURATE AERIAL APPLICATION OF HERBICIDES TO DRAINAGE CHANNELS WITH NEGLIGIBLE SPRAY DRIFT

Summary. Difficulties of access met with in Britain when applying dalapon to emergent water weeds in drainage channels led to work starting in 1964 on the development of a method of accurate aerial application of aqueous solutions of herbicide. The narrow, sinuous nature of the targets and the proximity of susceptible crops made it necessary to minimize spray drift and maintain a constant height and a slow speed. Nozzles designed to give large droplets were tested for droplet size and distribution. Selected nozzles were then tested from a helicopter in the field and the effect of their spray characteristics on the biological performance of dalapon was assessed. No daman occurred as a result of spray drift and satisfactory control of Phragmites communis, Typha angustifolia and T. latifolia was achieved with a lower dose of dalapon in a lower volume of spray than previously considered necessary for ground applications.
Une nouvelle technique pour l'application précise d'herbicides par voie aérienne sur les canaux de drainage, avec des risques négligeables d'entrainement