MOLYBDATE AND HYDROLYSIS OF PHOSPHATES 745 3. It is suggested that the effect is due to three factors. (a) If magnesia mixture is added to the reduced phosphomolybdate complex and the resulting precipitate analysed colorimetrically, recoveries of inorganic phosphate are low. (b) Free molybdic acid is reduced, giving molybdenum blue. Contrary to prevailing opinions, molybdenum blue is extracted from acid solutions by i8obutanol. (c) The specific extinction coefficient is about 4-5 times higher when the colour of the reduced phosphomolybdate complex is developed at 1000 than when it is developed at room temperature. This is true for most reducing agents except stannous chloride, with which a higher extinction is obtained at room temperature. 4. The effect is not observed under the milder experimental conditions of Weil-Malherbe & Green (1952). If it had occurred, a stannous chloride method of phosphate estimation, such as was used by these authors, would have been less subject to error than a method using aminonaphtholsulphonic acid. The author is indebted to Mr R. H. Green for much technical assistance.

A new technique is described in which 120-µ anionic resin spheres, impregnated with the radioactive gold isotope 198Au, are employed to simulate rabbit eggs. By their use, a study has been made of the pattern of egg transport in the Fallopian tube of the rabbit in vivo. (2) It has been shown that, in the first 8 hr after ovulation, the spheres have travelled 49% of the length of the tube. During the next 40 hr, movement down the tube is very slow until, at 48 hr after ovulation, the spheres are concentrated above the utero-tubal junction, 79% of the distance down the tube. (3) It has been possible to study the passage of the spheres into the uterus both at 56 and 64 hr after ovulation. Of the total number of spheres studied, 55% had passed into the uterus at the earlier and 90% at the later time. (4) Evidence is also included to show that the movement of the spheres reproduces the normal movement of eggs fairly closely. Their mean rate of progress is some 4% slower than the eggs, and this is due to a small proportion of the spheres lagging or even sticking at the site of transfer. It is also shown that the presence of spheres in the Fallopian tube does not affect normal egg movement. (5) The determination of the rates of tubai transport presented here will be a basis for further comparative studies upon the effect of certain hormonal treatments.

1. Moving-boundary electrophoresis of the mucin from the Cowper's gland of the boar revealed a sharp single peak at pH values from 1.1 to 9.0 and an isoelectric point of 1.1. 2. Neuraminidase treatment of the mucin, which removed at least 96% of the sialic acid groups, decreased the electrophoretic mobility at pH4 from -7.4x10(-5) (for the mucin) to -0.64x10(-5)cm(2)V(-1)s(-1). 3. Ultracentrifugal sedimentation values of s(20,w) showed a marked dependence on concentration. A hyperfine peak, similar to that given by ovine submaxillary secretion, persisted throughout the run at higher concentrations. Ultracentrifugal studies further showed a very low value for the diffusion coefficient (D(20,w) -1.57x10(-8)cm(2)/s). 4. Calculation of the approximate molecular weight from comparable s(20,w) and D(20,w) values gave a provisional value of 6.5x10(6). 5. Two proteins present in the boar vesicular secretion known as protein A and protein H (the haemagglutinating protein) were shown to promote the swelling of the mucin to form the characteristic rigid elastic gel of boar semen. It is suggested that protein A molecules particularly (mol.wt. 2.8x10(4)) cross-link with the long molecules of the mucin to form the seminal gel.

No abstract

Boar seminal plasma, vesicular secretion and epididymal plasma proteins were studied by gel disc electrophoresis at pH 4\m=.\5and 8\m=.\6and by isoelectric focusing in tubes and on plates using ampholines of pH range 3 to 10.The number of protein bands obtained in the gel disc electrophoresis was fifteen to twenty for all the samples. A similarity between the proteins of the seminal plasma and the vesicular secretion was greater at pH 4\m=.\5than at pH 8\m=.\6.The epididymal plasma showed a different separation picture.The better resolution of the isoelectric focusing revealed a greater number of proteins. Similar protein patterns were found for the vesicular secretion and the seminal plasma in the basic part of the pH range, where the majority of the proteins of these fluids are found. The proteins of the epididymal plasma, on the other hand, possess more neutral isoelectric points and their contribution to the seminal plasma is smaller than that of the vesicular secretion. Only a few of the epididymal plasma proteins and of the minor vesicular secretion proteins could be found in the neutral and acidic regions of the seminal plasma. This is largely the result of the dilution of these accessory secretions occurring during ejaculation.