摘要:

SUMMARYThe occurrence of some bacteriform Microsporidia from certain Crustacea and Insecta in Canada and in England is recorded.The numbers of hosts examined and those that were infected withPyrotheca incurvata, Octosporea muscae damesticae, Toxoglugea, SpiroglugeaandTelomyxaspp. innom., are tabulated.Descriptions of the bacteriform Microsporidia are given and illustrated. Differential diagnoses are given as far as possible.The effects of the parasites on the hosts and their distribution within the hosts are set forth.The lethal potentialities of the Microsporidia are indicated both in natural infections and by experimental ones.The economic importance and possible applications of these bacteriform Microsporidia are considered.

ISSN:0370-2774    

DOI:10.1111/j.1096-3642.1958.tb00566.x

出版商:Blackwell Publishing Ltd    

年代:1958

数据来源: WILEY

摘要:

SUMMARY1Data for the cranial capacities and for the dimensions of the foramen magnum have been derived from 198 chimpanzees, 223 gorillas, 69 orang‐utans and 575 men at various stages of development.2The pattern of endocranial growth in the extant apes is similar to that in man.3The age changes in the foramen magnum follow those in the endocranial cavity–some 95 per cent of adult size being reached by the time the first permanent molars are in place.4Comparison between these new data and the stated endocranial volumes of the Australopithecinae confirms that in this feature the South African fossils are ape‐like.5The cranial capacity and the area of the foramen magnum are sufficiently closely correlated to enable the one to be predicted from the other.6The relationship between the area of the foramen magnum and the cranial capacity of the Australopithecinae was apparently similar to that in extant apes and an estimate is made on this basis of the endocranial volume of an immature specimen ofParanthropus crassidens(SK 47) of which the skull base only is pres

ISSN:0370-2774    

DOI:10.1111/j.1096-3642.1958.tb00567.x

出版商:Blackwell Publishing Ltd    

年代:1958

数据来源: WILEY

ISSN:0370-2774    

DOI:10.1111/j.1096-3642.1958.tb00568.x

出版商:Blackwell Publishing Ltd    

年代:1958

数据来源: WILEY

ISSN:0370-2774    

DOI:10.1111/j.1096-3642.1958.tb00569.x

出版商:Blackwell Publishing Ltd    

年代:1958

数据来源: WILEY

摘要:

SUMMARY1The arrangement of the tracheal trunks is compared inCheyletus eruditue, Allothrombium fuliginosumandDinoihrombium tinctorius.2It is concluded that the condition inCheyletusarose by fusion of the cheliceral bases and the extension dorsally of paired atria.3The opening to the external air is in the last peritrematal chamber inCheyletus eruditus.

ISSN:0370-2774    

DOI:10.1111/j.1096-3642.1958.tb00570.x

出版商:Blackwell Publishing Ltd    

年代:1958

数据来源: WILEY

摘要:

SUMMARYThe occurrence of a colony of fur seals in South Georgia is recorded and the observed habits and interspecific relationships of the seals described. The colony is estimated to consist of between 8,000 and 12,000 seals, excluding pups. The ratio of harem bulls to breeding cows was found to be 1: 8‐4. The future prospects of the herd are discussed and it is suggested that expansion and increase in numbers may be expected to take place. The occurrence of fur seals in the South Orkneys is note

ISSN:0370-2774    

DOI:10.1111/j.1096-3642.1958.tb00571.x

出版商:Blackwell Publishing Ltd    

年代:1958

数据来源: WILEY

摘要:

SUMMARY1The statue of the clinid fish from the Conway River, North Wales, described by Fraser‐Brunner asParmclinus spinosus, has been a matter of doubt since its discovery.2The unique holotype has been re‐examined, and certain errors in the description corrected. It is considered to be identical with the Caribbean speciesStaihmonotus (Auchenistius) stahli.3The methods by which introduction of the specimen could have taken place are discussed, and it is concluded that the most likely is as an accidental introduction by a passing ship. A similar case is cited in this resp

ISSN:0370-2774    

DOI:10.1111/j.1096-3642.1958.tb00572.x

出版商:Blackwell Publishing Ltd    

年代:1958

数据来源: WILEY

摘要:

SUMMARY1An analysis has been made of the movements of biting, chewing and swallowing in the domestic rabbit. Techniques employed were dissection, direct observation of rabbits feeding, cinematography, still radiography and cineradiography.2During biting the lower jaw moves forwards so that the anterior and the lower incisors come together edge to edge. This observation casts doubt on Wood's theory that the lower incisor of the lagomorph is the lower homo‐logue of the posterior upper incisor.3Evidence has been given which suggests that the anterior upper incisors are worn and shortened by movement of the lower incisors upwards and backwards against their wear surface during biting. The transverse movement of the lower incisors during the grinding phase of chewing wears the posterior upper incisors and also maintains the chisel edge on the tips of the lower incisors. No movements have been seen whereby the remainder of the wear surface of the lower incisors is abraded: from examination of the teeth it is suggested that the level of this surface is maintained by being passed forwards across the cutting edge of the anterior upper incisors.4During chewing the lower cheek teeth move from without inwards on the side on which chewing is taking place during the grinding phase.5It appears that the tongue is functionally divisible into three parts: the diastemal portion is concerned with the procuring and manipulation of food and its passage backwards to the cheek teeth; the intermediate portion, which has a dorsal shield and lies between the cheek teeth, is responsible for placing the food on the lower cheek teeth and keeping it to the side on which chewing is taking place and passing it progressively backwards; and the posterior portion situated behind the cheek teeth is associated with the soft palate in providing temporary storage for chewed material prior to swallowing, and with the soft palate and pharyngeal musculature in swallowing.6The tongue movements and swallowing mechanism in the rabbit are compared with those in man, lambs and kid goats.7A functional theory to explain the evolution of the long diastema is put forward.8Movements of the temporo‐mandibular joint are also conside

ISSN:0370-2774    

DOI:10.1111/j.1096-3642.1958.tb00573.x

出版商:Blackwell Publishing Ltd    

年代:1958

数据来源: WILEY

摘要:

SUMMARY1The internal growth rings of the teeth of the crabeater seal(Lobodon carcinophagus)are described and the annual pattern established.2By examination of near term foetuses, recently weaned pups, half‐year‐old, one‐year‐old and older animals the probable pattern of dentine deposition in the first year is established. The neonatal line is conspicuous; a line marking the time of weaning is present and also a line which probably represents the pup moult. The rate of dentine deposition is discussed and it is suggested that lactation extends over about five weeks.3Using ages determined from the growth rings in the canine teeth, an average growth curve for body length has been constructed and is compared with earlier estimates of the rate of growth in the first few years.4Evidence is given which suggests that the average neonatal length is 45 in. The sizes subsequently attained by the two sexes are similar, though the largest females tend to be slightly larger than the largest males. The mean body length of animals over twelve years old is 89 $2–36 in.5The question of the age at sexual maturity is re‐examined and it is concluded that in the female sexual maturity is usually attained at an age of a few months over two years.6The age distribution of the two samples of crabeater seals is discussed. The oldest animals in the material were 19 years old on the basis of de

ISSN:0370-2774    

DOI:10.1111/j.1096-3642.1958.tb00574.x

出版商:Blackwell Publishing Ltd    

年代:1958

数据来源: WILEY

摘要:

SUMMARYThe various views that have been put forward of the asymmetry of the amphioxus larva are discussed, and a modification of Garstang's view is proposed. Upon this view, the asymmetry of the amphioxus larva is directly related to its mode of feeding; the essentials of this process in the young larva are discussed and it is concluded that the body cilia play an important part in the feeding process. The derivation of amphioxus from the Ascidiacea is discussed, and various points are indicated which suggest that the original position of the mouth in the ancestry of amphioxus was ventral, as Garstang suggested.

ISSN:0370-2774    

DOI:10.1111/j.1096-3642.1958.tb00575.x

出版商:Blackwell Publishing Ltd    

年代:1958

数据来源: WILEY