摘要:

SUMMARYThe unique holotype ofBrowneichthys ornatusWoodward has been reexamined. Illustrations of the specimen are published for the first time, and, although it has not been possible to add considerably to the text of the original account, a short redescription is included. The systematic position ofBrowneichthys ornatusis discussed. It is concluded that this species should not be retained in the family Saurichthyidae and its transfer to the family Coccolepidae is proposed.

ISSN:0370-2774    

DOI:10.1111/j.1096-3642.1958.tb00683.x

出版商:Blackwell Publishing Ltd    

年代:1958

数据来源: WILEY

摘要:

SUMMARYThis paper has presented certain demographic data of forty populations of house mice from English grain ricks. The populations are grouped into four density classes on the basis of the number of weaned mice per cubic metre. The resulting demographic averages of various density classes are then compared.Relatively little reproductive alteration occurred in rick populations in relation to density. The major “density effects ” so often observed in laboratory studies did not appear or were only moderately expressed in these data.Mortality rates of the populations revealed no dramatic or conspicuous change throughout the density classes studied (as evidenced by weight ratios and sex ratios).Fecundity of both sexes remained high throughout all density classes.Fertility revealed a significant decline in the highest density class, but it still remained at high levels. Pregnancy rates declined from 58 per cent in the low density class to 43 per cent in the very high density class. Average litter size fell from 6·23 to 5·11.Embryonic and fetal resorption increased significantly in the highest density class (14 per cent and 27 per cent).The general rate of reproductive increase declined with increasing density.The incidence of wounded males increased significantly in the highest density class (0·8 per cent to 21·1 per cent).Adrenal weights did not reveal adrenal hypertrophy in crowded populations.The relative stability of rick populations with increasing density is probably a reflection of the high quality of the habitat. Density effects are undoubtedly minimized by the favourable abundance and distribution of food and cover.It is of equal interest that individual populations in this relatively uniform habitat did show wide variations in their population size and structure. The fact that this variation is not obviously related to density, food, or cover, focuses attention on factors outside the normal realm of physical habitat as major population inf

ISSN:0370-2774    

DOI:10.1111/j.1096-3642.1958.tb00684.x

出版商:Blackwell Publishing Ltd    

年代:1958

数据来源: WILEY

摘要:

SUMMARY1This paper deals with a revision of the British species of the subfamily Aceosejinae together with a synonymic list of the species of the subfamily.2Keys are given for the separation of genera and species of the British aceosejines.3The following new synonymy is introduced:(a) ArctoseiulusWillmann andArctotarseiusWillmann are synonyms ofArctoseiusSig Thor.(b) ArctoseiodesWillmann is a synonym ofLeioseiusBerlese.(c) SeiopsisBerlese,JordensiaOudemans andBlattilaelapsWomersley are synonyms ofProctolaelapsBerlese.(d) GarmaniaNesbitt andParagarmaniaNesbitt are synonyms ofMelicharesHering.(e) ArctoseiopsisEvans is a synonym ofIphidozerconBerlese.(f) AceosejusSellnick is a synonym ofLasioseiusBerlese.(g) Lasioseius (L.)innumerabilisBerlese,Lasioseius alpinusSchweizer andLasioseius ventritrichosusSchweizer are synonyms ofHypoaspis hypudaeiOudemans.(h) Typhlodromus domesticusOudemans is a synonym ofMelichares agilisHering.(i) Typhlodromus tineivorusOudemans,Blattisocius triodonsKeegan andLasioseius similisSchweizer are synonyms ofLasioseius (L.) tarsalisBerlese.(j) Lasioseius fimbriatusHalbert andSeiulus amboinensisOudemans are synonyms ofLasioseius (L.) dentriticusBerlese.(k) Laelaps ligoniformisMichael is a synonym ofSejus muricatusC. L. Koch.(l) Arctoseius austriacusWillmann is a synonym ofGamasellus (Sess

ISSN:0370-2774    

DOI:10.1111/j.1096-3642.1958.tb00685.x

出版商:Blackwell Publishing Ltd    

年代:1958

数据来源: WILEY

摘要:

SUMMARY1The thelycum QfP. japonicusBate consists of two parts (i) an interior triangular plate, and (ii) a posterior pouch.2The formation of the pouch is described. It is a complicated process involving folding and tucking in of the lateral arms of the U‐shaped plate and anterior growth, notably of the transverse median portion of this plate.3The structure of the spermatophores is described, and their relation to the thelycum in an impregnated female. This description supports Heldt's work onPenaeus trisulcatusLeac

ISSN:0370-2774    

DOI:10.1111/j.1096-3642.1958.tb00686.x

出版商:Blackwell Publishing Ltd    

年代:1958

数据来源: WILEY

摘要:

SUMMARYThe giraffe in South Africa live entirely in the Eastern Transvaal, a lowveld region primarily of grass or veld with scattered bushes and low trees. The giraffe browse on a wide variety of trees in the spring and fall when few leaves are available, but in summer when all the trees are in foliage they are much more selective. The giraffe spend most of the day and part of the night feeding, especially the early morning and late afternoon. In the summer when food is abundant, the giraffe have more time during the day to chew their cud and lie down.The males spend part of the day fighting with each other. Such matches are seldom serious and often end in sexual play with one male mounting the other. The most common heterosexual activity was the testing of the females' urine by the male. There is no breeding season among giraffe, and the young are born all through the year.Giraffe are usually found in groups or herds, but they do not appear to communicate with each other, although they are capable of making sounds. The herds are loose associations of animals, generally with no definite leadership, and often include both adult males and females. Herds travelled very slowly, and often remained on the farm where they were studied for at least one year.The giraffe on Fleur de Lys farm have become used to farm conditions; they jump fences instead of breaking through them, and drink water from the cattle troughs, often walking among the cattle to do so.

ISSN:0370-2774    

DOI:10.1111/j.1096-3642.1958.tb00687.x

出版商:Blackwell Publishing Ltd    

年代:1958

数据来源: WILEY

摘要:

SUMMARY1The nymph ofChloeon dipterumis a pelagic animal living in ponds, Its plate‐like bilamellate gills are described.2By means of metachronal rhythmical movements of the gills, in which members of pairs beat synchronously, currents of water are set up over the body. These currents which are on the whole axial to the body explose water from all regions surrounding the body.3The gill and abdominal musculature is described and it is shown that a modification of normal musculature has occurred to provide direct muscles to the gill bases and also to make possible the habit of swimming by rhythmical movements of the abdomen rather than by limbs. These movements are lateral and are made about a vertical axis. Swimming is always preceded by a vigorous up and down movement of the caudal filaments. This movemelit about a transverse axis as in the tail flukes of a whale is then abandoned as the side to side movements of the abdomen take charge, when the animal swims aa does a fis

ISSN:0370-2774    

DOI:10.1111/j.1096-3642.1958.tb00688.x

出版商:Blackwell Publishing Ltd    

年代:1958

数据来源: WILEY

摘要:

SUMMARY1Laboratory‐breeding stocks of the multimammate mouse,Rattua (Mastomys) natalensis, have been maintained since 1939 and have become of increasing importance in medical research. This mouse has been used primarily as the standard test‐animal in routine diagnostic and experimental work in plague.2It is highly susceptible to experimental infection withSchistosoma mansoni, and in consequence has assumed importance in bilharzia research.3A high proportion (30 to 50 per cent) of animals dying in the colony from natural causes have been found to be suffering from spontaneous adenocarcinoma of the glandular stomach—a condition which is extremely rare in animals other than man. The multimammate mouse promises to be an impor tant experimental animal in cancer research.4The taxonomic status of the multimammate mouse has not been satis factorily defined. Some of its anatomical and physiological features areRattus—like, othersMus—like, while others appear to be unique (e.g. the presence of a prostate gland in the female).5The known similarities and differences between the multimammate mouse, the laboratory rat and the laboratory mouse are tabulated. On the available data it is hard to say whether it should be classified as a subgenus ofRattus, as it is at present, or whetherMastomysshould be given generic rank or made a subge

ISSN:0370-2774    

DOI:10.1111/j.1096-3642.1958.tb00689.x

出版商:Blackwell Publishing Ltd    

年代:1958

数据来源: WILEY

摘要:

SUMMARYRhizorhina ampeliscaeHansen is recorded from Guernsey and the Clyde area.Five species of the genusSphaeronellaare recorded from British waters for the first time. One of these,S. pikei, is a new species.Sphaeronella elegantulaHansen is shown to be a synonym ofS. leuckartiSalensky.The larva ofS. danicaand the male ofS. longipesare described for the first time.The following new hosts are recorded.Aora typicaparasitized byS. leuckarti. Erichthonius brasiliensisparasitized byS. danica. Ampelisca tenuicornisparasitized byS. frontalis. Pontocrates arenariusparasitized byS. pikeisp. n.

ISSN:0370-2774    

DOI:10.1111/j.1096-3642.1958.tb00690.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.tb00691.x

出版商:Blackwell Publishing Ltd    

年代:1958

数据来源: WILEY