Methods are described whereby a factorial experiment was set up to test the effects on 40 potato plants, growing in 15 Kg. pots of soil, of the three factors: (S) steam sterilization of soil, (H) infection of soil with about three million eggs ard larvae of Heterodera rostochiensis per pot, and (D) injection of soil with 10 ml. of D-D per pot.

Data from the infected half of the pots were also used to test the effects of factors (S) and (D) on the eelworm population.

The data from 10 plant criteria yielded three statistics: the variance ratio (F), the coefficient of variability (V), and the Normal difference (t) corresponding to each factor and interaction. From an examination of these, the following two criteria are selected as, between them, displaying all the significant treatment effects of the experiment:

A factorial experiment involving the presence and absence of three factors: steam sterilization (S), infection with some three million eggs and larvae of Heterodera rostochiensis per pot (H), and injection of 10 ml. of D-D per pot (D), the factors applied in that order, was carried out to ascertain the effects on the growth of 40 potato plants in pots containing 15 Kg. of soil.

In the event, the D-D was lethal to the great, majority of eelworms, so that treatments labelled (hd) and (hsd) were effectively reduced to (d) and (sd). This fact greatly complicated the analysis, but nevertheless enabled certain conclusions to be drawn. The use of this factorial design may be criticised in the face of this antagonistic action between, two of the factors. Nevertheless, the effects of H and D acting together on the plants was a subject of interest; the real fault in design lay in using too high a concentration of D-D, or in not using a series of concentrations. The fact that the concentration used was too high emerged from the experiment and was not known beforehand.

In an earlier paper Goodey (1940) gave a detailed description of the morphology of three species of Anguillulina viz.: A. multicincta (Cobb) Goodey, A. erythrinae (Zimmermann) Goodey and A. robusta (de Man) Goodey. All three species are associated with plant roots: A. multicincta is a parasite of banana roots, A. erythrinae is parasitic on the roots of certain common grasses and cereals such as Agrostis stolonifera, Lolium perenne and oats (the writer has also found it on hop roots), A. robusta though associated with grass roots has not, to the writer's knowledge, been found within plant tissues. In the case of all three species phasmids were easily recognized on the female tails and were described and figured but they were not seen on the male tails and it was assumed that they were probably absent.

Six new species of Spirurids are described from terrestrial vertebrates from various countries. They are Camallanus macabukae n.sp. and Procamallanus brevis n.sp. from bull-frogs in S. Africa, C. multilineatus n.sp. from Rana catesbiana in N. America, Tanqua gigantica n.sp. from Python reticulatus and Naja. hannah in E. Indies and S.E. Asia, respectively, Ancyracanthopsis madagascariensis n.sp. from Dryolimnas cuvieri in Madagascar, and Physaloptera singhi n.sp. from the monkey (?) in S. America. Three species inquirendae, Camallanus sp., Streptocara sp. and Physaloptera sp. are also described. Some new morphological features in Habronema mansioni and Physaloptera paradoxa are discussed and the female of Hartertia zuluensis is described for the first time.

Transverse fission of Cysticercus pisiformis begins in the liver and is usually completed there. It is brought about by one or two annular constrictions which. ultimately result in the complete fission of the original bladder-worm into two or three parts. The posterior segments thus formed are normally acephalic.

Histologically, fission involves an initial hypertrophy of the cuticle and subcuticula at the zone of constriction, followed by their degeneration and loss, and by the increase and consolidation into a slender cord of the muscle and parenchyma fibres. With the rupture of the cord and the sealing up of the broken ends, fission is complete.

The majority of the bladder-worms do not undergo fission, but the process is apparently spontaneous and quite normal for the species. Its cause is unknown, but it is thought to have a phylogenetic significance.

The previous observations of the author and others on the development ot Cysticercus fasciolaris and C. pisiformis have been confirmed and amplified by experimental studies, and the developmental processes of the two forms are compared. While definite information has been obtained on the age of the various developmental stages, there is considerable variation due to the subtleties of the host-parasite relationship.

The study of the development of the rostellar hooks of taeniids has been extended by the use of differential staining, histochemical tests and polarized light, and new facts, such as the chemical and optical differences existing between cuticle and hooklets and between blade and base of hooks, have been brought to light.

Acuaria anthuris, the type species of the genus Acuaria, is described in detail and A. scutata is considered to be synonymous with it.

Acuaria skrjabini from Passer domesticus has been described and compared with the original description. It is a new record for India and Hyderabad.

Acuaria kungi n.sp. from Saxicoloides fulicata is described and compared with related species.

Acuaria sp. is recorded from Pastor roseus.

A new species of Cheilospirura from Accipiter nisus is described and compared with related species.

The writer in 1934 briefly described this nematode which was collected from the common musk-shrew at Hyderabad Deccan, creating for its reception the new genus and species Gastronodus strasseni. The following account deals with the anatomy of the worm and the close relationship which exists between the genera Gastronodus Singh and Spirocerca Railliet and Henry, 1911.

This worm is of common oċcurrence in the musk-shrew, Crocidura caerulea, at Hyderabad and it forms largo nodules on the stomach walls of the host. In certain cases smaller nodules were also found in the mesentery. These are medium sized worms and when freshly extracted appear blood red in colour. The body is coiled and generally flexed at the extremities. In males and young adult females the body is of almost uniform diameter with blunt anterior and posterior ends, whereas in fully grown and gravid females the posterior 2/3 of the body is distinctly thicker than the anterior portion. The males are slender and smaller than the females. The cuticle is thick and bears fine transverse striations which are set quite close together. Irregular transverse wrinkles are also present on the body wall. The cervical papillae are located at the level of the nerve-ring and have the appearance of fine bristles.