摘要:

SUMMARYA review of the morphological criteria on which the species ofRenicolaare separated is given and an analysis of the value of these criteria is made, Three new host records for the genusRenicolaare given and the worms found are described. The pathology of the infected bird's kidney is discussed.The species of cercariae of the “Rhodometopa” group found during the present work are listed and two new species are described. Some general observations on the anatomy of these cercariae are made. The miracidia ofRenicolasp. fromPuffinus puffinusare described. The development of the sporocysts of the “Rhodometopa” group of cercariae is described and a new interpretation of the structure of the body‐wall of these sporocysts is presented. Observations on the emergence of cercariae from infected snails are described, also observations on the behaviour of these cercariae. Experimental infection ofTurritella communiswith the eggs ofRenicolasp. is described and the results are discussed.A new host for the metacercariae of the “Rhodometopa”‘ group(Clupea sprattus)is recorded. Two types of metacercarial cysts are described. The infection rate in sprats is discussed. Attempts to bring about excystation by means ofin vitrodigests are described, also unsuccessful attempts to produce experimental infection ofRenicolaspp. in birds. The connection between the sprat as an intermediate host and the high infection rate ofRenicolasp. inPuffinus puffi

ISSN:0370-2774    

DOI:10.1111/j.1096-3642.1956.tb00423.x

出版商:Blackwell Publishing Ltd    

年代:1956

数据来源: WILEY

摘要:

SUMMARYThe relationship between the length of the molar row and the length of the lower jaw in mammals is expressed by the allometry equation y=bxk.A single formula cannot be applied to all the Eutheria because the value ofk,the constant differential growth ratio, varies from group to group.Variation inkwould appear to be adaptive, for it increases from a value of less than unity in carnivores, through insectivores and omnivores, and exceeds unity in herbivores.The value of the constantbdecreases askincreases, with the result that most mammalian skulls have the same length of molar row when the jaw length lies between 90 and 110 mm.When the full complement of molars is not present, there is a reduction in the extent of the molar row. In groups with a common ancestry, this reduction is proportional to the number of teeth which are lost, but a history of tooth enlargement may partly compensate for the decrease.The zalambdodont Insectivora are anomalous in that the molar row occupies proportionally less of the jaw than in most mammalian orders. The genera may be arranged in a graded sequence, the first members of which overlap the remaining Eutheria while the final members depart widely.InTenrecandHemicentetesthe length of the molar row is independent of jaw size.In view of the variation in the value of the constantsbandkfor both the zalambdodonts and the other Eutheria the paurodont/zalambdodont line cannot be set in contrast to a marsupial/eutherian line.These conclusions apply with equal force whether the molar row is related to the total jaw length or only to that part of the jaw lying posterior to the last pre‐mola

ISSN:0370-2774    

DOI:10.1111/j.1096-3642.1956.tb00424.x

出版商:Blackwell Publishing Ltd    

年代:1956

数据来源: WILEY

摘要:

SUMMARYFur seals on Marion Island, provisionally identified asArctocephalus gazellaPeters, are described and compared with two other species of southern fur seal.There are a few hundred fur seals on Marion Island, of which about 160 to 170 are breeding males. The fur seals live on crustaceans, cephalopods and fish. Females breed in the summer (November) but are not visibly pregnant till April. Pups moult in March, and the older animals somewhat earlier.Former sealing operations are discussed. There appear to be no good prospects for profitable future operations. The small size of the herd has not been adequately explained.

ISSN:0370-2774    

DOI:10.1111/j.1096-3642.1956.tb00425.x

出版商:Blackwell Publishing Ltd    

年代:1956

数据来源: WILEY

摘要:

SUMMARYThree fossil Felinae are described. These are a leopard differing only slightly from the living species, and namedPanthera pardus incurva;and two species of lion‐like animal, which are not identical with the living species. The specimens of the latter two species are very fragmentary, and they have not been named, but are merely referred to as the Swartkrans and the Kromdraai “lions”. It is suggested that the latter may possibly be identical withPanthera shawi(Broom).It is concluded that the differences in the feline faunas of the deposits at Sterkfontein, Swartkrans and Kromdraai indicate some difference in the ages of the dep

ISSN:0370-2774    

DOI:10.1111/j.1096-3642.1956.tb00426.x

出版商:Blackwell Publishing Ltd    

年代:1956

数据来源: WILEY

摘要:

SUMMARYThe whole of the fossil canid material at present available from the Transvaal caves has been examined.Canis terblanchei(Broom) is considered to be a valid species, but the type specimen does not come from the Kromdraai deposit, as Broom originally stated. This species has not been found at any of the three main deposits, but at least one additional specimen lias been found at the site known as Coopers.A new species,Canis brevirostris,is described from the Sterkfontein type site. This species does not resemble either of the living South African jackals, and it has not been found at Swartkrans or Kromdraai.A large number of specimens, including material from all the three main sites, is considered to belong to a form differing only slightly from the livingCanis mesomelas.Although the material may be somewhat heterogeneous it has not been found possible to sub‐divide it, and all the specimens have been referred to a subspecies of the living form which has been namedCanis mesomelas pappos.The position ofCanis antiquus(Broom) remains undecided.A mandibular fragment from Swartkrans is provisionally referred toVulpes pulcherBroo

ISSN:0370-2774    

DOI:10.1111/j.1096-3642.1956.tb00427.x

出版商:Blackwell Publishing Ltd    

年代:1956

数据来源: WILEY

摘要:

SUMMARY1Comparisons have been made between fifty‐eight dimensions of the milk teeth of(a)the male and female chimpanzee,(b)the male and female gorilla.2There is no evidence that the milk teeth of the male chimpanzee differ in size from those of the female.3The milk teeth of the male gorilla are, on the average, 3 per cent bigger than those of the female.4These differences appear before the hormonal factors responsible for the pubertal growth spurt become operative, and may be controlled geneticall

ISSN:0370-2774    

DOI:10.1111/j.1096-3642.1956.tb00428.x

出版商:Blackwell Publishing Ltd    

年代:1956

数据来源: WILEY

摘要:

SUMMARYThe lateral musculature of the fish‐like chordates has been examined in an effort to find reasons for the peculiar pattern of the myomeres. There are three distinct types of myomeres: amphioxine, cyclostomine and piscine. All have in common the function of bending their possessors' bodies from side to side to provide locomotor force. In all cases pull is applied obliquely to the long axis of the body. The myomeres pull at once latero‐craniad and laterocaudad to bend the body from its position of equilibrium, or rest, into concavity. If continued, this movement would lead to a condition of instability, in which the vectors of the forces applied would pass across the axis of bending and the body would be distorted. However, the length of the body and its resistance to compression prevents this. Also, during locomotion, restorative forces are developed on the convex side of the body to supplant the original bending movement and the body passes through the equilibrium position to become concave on the opposite side. These reactions follow one another through myomere after myomere from head to tail along the body of the animal; the result is lateral waves passing rapidly down the body, the reaction of which with the water provides locomotion. Each myomere covers several vertebral segments and succeeding myomeres overlap. This allows the bending to progress smoothly along the body as each myomere affects not only its own section of the body but also those of its neighbours.The myomeres gain attachment to vertebral centra, neural and haemal spines (or ribs) and the connective tissue septa between these structures. Secondary attachments by means of longitudinal ligaments, formed by the apposition of deep myosepta, often occur, especially among the Chondrichthyes.The mechanical advantage of a segment of the lateral musculature is very small, but it approaches unity among the tunas, In these fish the muscle is concentrated in the body region, while the caudal peduncle supports long tendons running to the caudal fin.Intermuscular bones appear in the myosepta of many species of fish. These appear to have been developed in response to stresses and strains set up by the musculat

ISSN:0370-2774    

DOI:10.1111/j.1096-3642.1956.tb00429.x

出版商:Blackwell Publishing Ltd    

年代:1956

数据来源: WILEY

摘要:

SUMMARYThe heart ofLacerta viridisis described. It has two auricles and a ventricle, the latter partially subdivided into three parts. The roles of the three parts of the ventricle have been the matter of some discussion. We have attempted to analyse the functions of the various parts of the heart by radiography.The radiological anatomy of the heart and great vessels ofLacerta viridishas been described and cine‐radiographs showing the passage of the radioopaque medium, thorotrast, through the heart have been made by both “direct” and “indirect” methods.The interpretation of the radiographs shows that there is a marked difference in treatment of the blood entering the heart by way of right and left auricles. The blood from the lungs and left auricle passes into the left portion of the ventricle (cavum arteriosum) and is sent to the right systemic arch and to the carotid vessels of both sides.The blood from the general body circulation entering the heart through the sinus venosus and right auricle is divided into two portions. One passes into the right dorsal portion of the ventricle (cavum venosum) and is sent out mainly through the left systemic arch. The other portion passes from the dorsal portion of the ventricle into the ventral portion (cavum pulmonale) and so into the pulmonary arteries.As the ventricle is only partially divided there is some mixture of blood from the two auricles but our results show that the degree of mixture

ISSN:0370-2774    

DOI:10.1111/j.1096-3642.1956.tb00430.x

出版商:Blackwell Publishing Ltd    

年代:1956

数据来源: WILEY

ISSN:0370-2774    

DOI:10.1111/j.1096-3642.1956.tb00431.x

出版商:Blackwell Publishing Ltd    

年代:1956

数据来源: WILEY