摘要:

In the genusEleutherodactylus, development is wholly embryonic. Among other features of ontogeny which are thereby modified is the development of behaviour. Within the egg envelope, the embryo is largely still, but wriggles from time to time. These movements represent all that remains of the axial swimming behaviour of larval Amphibia. The embryo develops normally when removed from the envelopes, and its reactions to light touch can then be studied from day to day. InE. martinicensis, which develops from first cleavage to hatching in 13‐14 days, the first movement of the legs is seen during trunk wriggles at 7 1/2 days, but a day later they can move independently. The first reaction of the leg is a slow withdrawal; at 9 1/2 days flexion is followed by a vigorous extension. By then, reflexes affecting all four limbs can be elicited.Towards the end of embryonic life, limb movements can be maintained in continuous cycles, and the animal can then swim. When it is allowed normally to emerge from the envolopes, the juvenile toad, smaller than a house fly, can jump a distance of over a foot. These observations are discussed in relation to the ontogeny of behaviour in other vertebrates, particularly in regard to the views of G. E. Coghil

ISSN:0370-2774    

DOI:10.1111/j.1469-7998.1965.tb05170.x

出版商:Blackwell Publishing Ltd    

年代:1965

数据来源: WILEY

摘要:

Six species of anurans were studied representing four of the five anuran families occurring in Malaya and Singapore. Food items, variation in the diet, and the relationship between predator and prey size are discussed. Singapore anurans show various degrees of selectivity for particular types of prey. In general, availability of prey in the habitat, the size of the prey animals and the size of the predators, especially the gape of the mouth, determined the diet.

ISSN:0370-2774    

DOI:10.1111/j.1469-7998.1965.tb05171.x

出版商:Blackwell Publishing Ltd    

年代:1965

数据来源: WILEY

摘要:

The development ofEuterpina acutifronsis described from observations of individuals reared in the laboratory. The characteristics which enable the various stages to be identified have been listed and the feeding mechanism of the larvae described. Differences from the usual developmental pattern of the Harpacticoida are noted and it is suggested that these are related to the pelagic habit ofEuterpina. Dimorphism in the male is described and the course of development of the dimorphs is shown to differ from schemes previously suggested for other copepods. Dimorphism, which is manifested at the moult of the third copepodid, is shown to be independent of temperature.

ISSN:0370-2774    

DOI:10.1111/j.1469-7998.1965.tb05172.x

出版商:Blackwell Publishing Ltd    

年代:1965

数据来源: WILEY

摘要:

Observations are given on the parasitism ofHomorocoryphus nitidulus vicinus(Walker) by the African tachinid flyGlaurocara flavaThomson, and the hitherto unknown immature stages ofG. flavaare described and illustrated. The female ofG. flavais shown to be larviparous, producing abundant highly specialised planidium larvae very closely resembling those of the little‐known tribe Ormiini. The systematic affinities ofGlaurocaraare briefly discussed and it is suggested, in view of the reproductive habits and the structure of the first instar larvae, that this genus must be very close phylogenetically to the Ormiine Tachinida

ISSN:0370-2774    

DOI:10.1111/j.1469-7998.1965.tb05173.x

出版商:Blackwell Publishing Ltd    

年代:1965

数据来源: WILEY

摘要:

The reproductive system ofHydrocena monterosatianaGodwin Austen&Nevill, is described and is simpler in construction than those of other Neritacea. Evidence of fluctuating reproductive condition is given although breeding appears to persist throughout the year. Breeding fluctuations are related to changes in rainfall and their nature is compared with taht in other gastropods from the same locality.

ISSN:0370-2774    

DOI:10.1111/j.1469-7998.1965.tb05174.x

出版商:Blackwell Publishing Ltd    

年代:1965

数据来源: WILEY

摘要:

The presence and distribution of two groups of enzymes has been determined histochemically on sections of the schistosome‐bearing snailAustralorbis glabratus.By the use of specific inhibitors, attempts have been made to characterize further the enzymes occurring in the various organs and tissues.As a result of this study it has been found that alkaline and acid phosphatase are widely distributed but have identical localizations only in the kidney and albumen gland. Both enzymes react typically to the action of the usual inhibitors.Among the non‐specific esterases. an enzyme corresponding to the mammalian A‐type esterase (aromesterase) is present in the brain; while a B‐type esterase (aliesterase) is located in the digestive gland, intestine, and on the glandular region of the foot surface.A “true” lipase (an esterase acting on an undissolved substrate) is found principally in the albumen gland, with an indication of its presence in the digestive gland and in portions of the digestive tract.An enzyme with the properties of an acetylcholinesterase occurs in the radula sac, oesophagus, preputium, junction of carrefour and oviduct, and amoebocytes. A positive reaction for cholinesterase is also obtained with frozen sections of brain but, although this enzyme has been shown biochemically to hydrolyse acetylcholine and is inhibited by low concentrations of eserine. it is remarkably resistant to the action of organophosphorous compounds, and its true nature cannot he stated wit

ISSN:0370-2774    

DOI:10.1111/j.1469-7998.1965.tb05175.x

出版商:Blackwell Publishing Ltd    

年代:1965

数据来源: WILEY

摘要:

Six embryos of the eyed lizard (Lacerta lepida) with malformations such as short upper jaw, microphthalmia, abnormal fore‐brain, cleft palate, absence or deficiency of the pituitary and tail defects are described. Embryos of the common lizard (Lacerta vivipara) and adder (Vipera berus) with microphthalmia and cleft palate, and of a sand lizard (Lacerta agilis) showing partial Siamese twinning are also reported. The aetiology of these malformations, and the well‐known occurrence of similar conditions in birds and mammals, is discus

ISSN:0370-2774    

DOI:10.1111/j.1469-7998.1965.tb05176.x

出版商:Blackwell Publishing Ltd    

年代:1965

数据来源: WILEY

摘要:

Observations on the fauna of a heated, fully saline dock have been made by diving and by using suspended test panels. The seasonal abundance and breeding of native and immigrant species are described. The effects of subsequent cooling of the dock and the appearance of additional native species in the fauna are described and discussed.

ISSN:0370-2774    

DOI:10.1111/j.1469-7998.1965.tb05177.x

出版商:Blackwell Publishing Ltd    

年代:1965

数据来源: WILEY

摘要:

Lithobius variegatusandL. forficatusoccupy similar ecological niches and frequently occur together although there are differences in their distribution in the British Isles. An investigation of their food and reproductive cycles, being a preliminary step towards a further understanding of their ecological relationships, is described.Lithobiomorph centipedes have hitherto been regarded as wholly carnivorous, but it is shown that these species feed on litter as well as small litter animals, the presence of litter in the guts of these species not being connected with the presence of animal remains. WhereasL. forficatustakes litter throughout the year,L. variegatusdoes so mainly in the winter.Both species appear to lay eggs for a considerable part of the year, though there appears to be only a short period of sperm transfer in spring. It is suggested that the long oviposition period may prevent the loss of the entire brood in a dry summer. The succession of epimorph stadia inL. variegatusis described.L. forficatuswas more common thanL. variegatusin the drior part of the woods studied.

ISSN:0370-2774    

DOI:10.1111/j.1469-7998.1965.tb05178.x

出版商:Blackwell Publishing Ltd    

年代:1965

数据来源: WILEY

摘要:

The characters used for specific diagnosis in the subgenusHystrixhave been studied to determine their constancy as specific characters and their geographical variation within the species. As a result three species are recognized, namelyH. indica, H. cristataandH. africaeaustralis. H. galeatais considered a synonym ofH. cristata, andH. stegmannia synonym ofH. africaeaustralis. The morphological differences betweencristataandafricaeaustralisin East Africa are not continued clinally within these species. Betweencristataandindicasome of the diagnostic characters vary clinally, others change abruptly.

ISSN:0370-2774    

DOI:10.1111/j.1469-7998.1965.tb05179.x

出版商:Blackwell Publishing Ltd    

年代:1965

数据来源: WILEY