336                                              ABSTRACTS

congo-red were seen to have been intensified ; whilst the micellar substratum remained
intact. In the second phase the micellar substratum was found to be entirely disorga-
nised, double-refraction ceased, and both microchemical and staining reactions disappear-
ed. Evidence is put forward to show that the cyto clastic micro-organisms, which
include vibrionic and coccoid forms, are stages in the life-cycle of a single polyphasic
species.

With regard to the functional attributes of the indigenous protozoa, as investigated
the authors in the species of the genera C ycloposthium, Paraisoiricha, Didesmis, Ble-
pharocorys and Blepharocouns, the digestion of strach grains and iodophile micro-
organisms was observed. Ingestion of cell-wall substances by these protozoa was either
very little or altogether absent. It is said that the size of the particles acted as a.
limiting factor. Only small fragments were ingested and these were, in the majority
of cases, already in process of disintegration through the action of adherent cyto
clastic mirco-organisms. The authors, on these grounds, conclude that the protozoa
are not primary agents in effecting disintegration of cell-wall substances in the caecum.

Based on their observations the authors have discussed in detail the presence and
characteristics of an iodophile microflora with reference, in general, to the establishment
of a functional field and, in particular, to the organisation of carbohydrate metabolism
in the caecum. A symbiotic, rather than parasitic, relationship is emphasized
[H. N. R.].

Tick borne diseases. W. O. NEITZ, and P. J. Du TOIT (1938). (Jour.
S. A. Vet. Med. Assoc. 9, 85-124).

THE authors have described the animal and human diseases transmitted by the two
families of ticks, viz., the Argasidae and Ixodidae. The former transmit: (1) spirochae-
tosis which includes : (a) Relapsing fever in man conveyed through the agency of
Ornithodorus genus, while wild rodents act as reservoirs ; (b) Avian spirochaetosis,
Argas persicus being the vector of Spirochaeta anserina; (c) spirochaetosis due to S. theileri
and conveyed through Boophilus sp. and Rhipicephalus evertsi. (2) Aegyptonellosis
in fowls, geese and ducks caused by Aegyptonella pullorum and conveyed through A .
persicus. The Ixodidae are responsible for : (1) Piroplasmosis including (a) Redwater in
cattle caused by B.bigemina and transmitted through various species of Boophilus, Rhipi-
cephalus and Haemophysalis ; (b) Piroplasmosis of sheep caused by B. ovis and conveyed
through the adults of R. bursa ; (c) Equine Piroplasmosis caused by B. caballi and Nut-
tallia equi and transmitted through Dermacentor silvarum and species of Hyalomma and
Rhipicephalus ; (d) Biliary fever in dogs caused by Piroplasma canis, the vectors
being H. leachi and R. sanguineus which carry the infection through all stages of
development; (e) Babesiosis in dogs caused by B. gibsoni through H. bispinosa
(2) Theileriasis including (a) Theileria annulata infection in cattle through H. dro-
medarii asiaticum; (b) T. dispar infection in cattle through adults of H. detritum
mauretanicum and H. impressum near planum; (c) T. parva infection in cattle
through different species of Rhipicephalus ; (d) T. mutans infection in cattle through
R. evertsi and R. appendiculatus ; (e) T. ovis infection in sheep through R. bursa
(3) Anaplasmosis including (a) Anaplasma marginale infection of cattle through
different species of Boophilus, Ixodes ricinus and H. punctata; (b) A. ovis in sheep