Direct microscopic and culture counts were made on samples of rumen contents obtained by stomach tube from each of 25 cows at monthly intervals during 3 months. The ration was timothy hay plus various amounts of cottonseed meal, rolled barley, and salt. No correlation between different rations and differences in the microbiota could be detected. Streptococcus bovis was identified by its rapid growth in the feed medium and showed counts ranging between 2 × 10⁵ and 1.4 × 10⁸. Most animals showed a S. bovis count between 1 and 20 million with an average of about 10 million per milliliter. The characteristics of some rumen strains are described. The cellulose-digesting bacteria were referable to four chief groups and the numbers of each were recorded. The cellulolytic cocci varied in almost every character studied. Two types were distinguished as representing the greatest divergence. Ruminococcus albus n. sp. differs from R. flavefaciens in being Gram-negative, forming little or no yellow pigment, and producing no succinic acid. A cellulose-digesting sporeformer, Clostridium lochheadii n. sp., was found in many of the samples. It was extremely active in digesting cellulose, exceeding in this respect the species of anaerobic cellulose digesters previously isolated. Spores were formed in abundance but rapidly disintegrated and many strains were lost before subculture. Clostridium longisporum n. sp. was encountered during the investigation and is described.

Zonas citoplasmáticas de atividade redutora de TTC foram evidenciadas em células de Proteus vulgaris examinadas ao microscópio eletrõnico. As experiências foram realizadas em vários intervalos de tempo, sendo a reação, em alguns casos, estabilizada por meio de formol. Verificou-se que as granulações de formazana podiam ser removidas no interior do corpo bacteriano por meio de tratamento com acetona. O bombardeamento pelos eléctrons, quando os germes não tinham sido fixados com formol, determinou a saída das granulações do interior dos bacilos, deixando vestígios de sua presença (rompimento das membranas celulares nos pontos onde estavam localizados). A fixação com formol evitava a saída dos grânulos. O acúmulo dos cristais de formazana, internamente, nos pólos ou ao longo do corpo bacteriano, provoca sérias alterações morfológicas.<br>Cells of P. vulgaris incubated in plain broth (4 hours at 37 C) were treated with TCC in final concentration of 0,1 per cent at 37 C. They presented sites of TTC reduction as granules with volumes proportional to the time of contact with TTC. In microorganisms not fixed with formaldhyde, most of the granules during the electron microscopy ruptured the bacterial membranes leaving remains of these, like "ghosts", in the sites where the granule had been located: in rare cases large granules still were seen deforming the bacilli, whit a crystalline contour. When the cells were fixed with formaldehyde the granules remained in the microorganims. They could be removed from the cells by treatment with acetone leaving empty collapsed membranes.

The application of solutions of inorganic phosphorus fertilizers to crop residues before the residues are tilled into the soil is now a widespread practice in the Southwest. This practice is centered around the hope that the fertilizer phosphorus will remain at a higher level of availability as a result of this procedure than if it were added directly to the soil. The hypothesis is that phosphorus fixed by microorganisms during the decomposition of the crop residue is only temporarily unavailable to plants. Phosphorus fixed by this method presumably would be made readily available to plants during the latter stages of decomposition of the residues in contrast to the irreversible fixation by the inorganic constituents of the soil. Results with wheat straw and wheat straw composts containing tagged phosphorus indicate that a relatively greater amount of phosphorus is utilized by plants from compost than from noncompost material. The compost had lost 40 to 50% of its original weight as a result of decomposition before being added to the soil. On the other hand, results with phosphorus-free extracted oat straw showed that the less decomposed material (oat straw plus KH₂PO₄) supplied more P to ryegrass growing on Mohave clay loam than the compost (oat straw composted with KH₂PO₄). However, the extracted oat straw composts did not decompose to an extent to exceed 20% before being added to the soil. According to the data obtained, it must be concluded that there is no particular advantage of adding liquid phosphoric acid fertilizers directly to straw before incorporating them into calcareous soils over the practice of applying the fertilizer and straw residues independently.