ISSN:0370-2774    

DOI:10.1111/j.1469-7998.1965.tb04637.x

出版商:Blackwell Publishing Ltd    

年代:1965

数据来源: WILEY

摘要:

Understanding of the control of growth in the locust (Locusta migratoriaL.) is presented as a problem of the relationship between “nature” as represented by genetic information and “nurture” as represented by the locust's food and by the environmental temperature.Emphasis is placed on the role of proteins in the translation of the genetic code and on the formation of protein species from genes according to the model given by Jacob&Monod. In insects, neurosecretion may influence protein metabolism at the level of mRNA formation in the nucleus, and it is suggested that the mode of action is suppression of the negative feedback of the metabolite on to its specific gene locus. The release of neurosecretory material is related to food intake, information about which is relayed from stretch receptors in the pharynx,viathe frontal ganglion and frontal connectives to the brain. Surgical interference with this pathway leads to a complete cessation of growth in the animal.Studies on the action of fluctuating temperatures on the growth of the locust also show hormonal involvement. Under certain temperature regimes the corpora cardiaca is empty of neurosecretory material but there is no evidence of failure of its formation. It is thus assumed that it is being secreted and utilized, yet growth is slow or nonexistent. It is suggested that under these conditions protein metabolism is maximally stimulated as different protein species are needed to meet different requirements imposed by the changing environmental temperature.A model has been constructed which suggests a common basic mechanism to these and other phenomena. The model is formalized by the application of simple Boolean

ISSN:0370-2774    

DOI:10.1111/j.1469-7998.1965.tb04638.x

出版商:Blackwell Publishing Ltd    

年代:1965

数据来源: WILEY

摘要:

A detailed study of the reproductive habits ofRhinopoma kinneari(Wroughton) inhabiting a semi‐arid region of India (Jodhpur) was made to fill in the paucity of such information in the Family Rhinopomatidae.The reproductive pattern ofRhinopomacan be related to its seasonal movement which occurs just before and immediately after its winter torpor. The testes are permanently abdominal and these together with the accessory reproductive organs experience an annual sexual cycle. The females are monoestrous, breed in March and bring forth a single young during July‐August. Pregnancy lasts for at least 123 days and parturition occurs by head presentation. The young are weaned after six to eight weeks of suckling and attain sexual maturity in their second year of

ISSN:0370-2774    

DOI:10.1111/j.1469-7998.1965.tb04639.x

出版商:Blackwell Publishing Ltd    

年代:1965

数据来源: WILEY

摘要:

The structure and function of the stomachs of nine bivalves are examined. These animals belong to the Gastrotetartika, Gastrotriteia, and Gastropempta, the three orders of the Polysyringia, a new sub‐class of the Bivalvia suggested by Purchon (1960a). It is found that in all three orders there are common ciliary tracts and grooves. For example, tracts are always found in association with the duct openings, and a distinction between the right duct tract and the posterior sorting area is drawn. Another tract which is a constant feature of these stomachs, but which has not been noted before, is the antero‐dorsal tract. A generalized polysyringian stomach is constructed. All the stomachs examined function similarly, there being set up in the lumina circulating currents of the gastric fluid. In general, large particles and masses of particles are recirculated until they are broken down, and small heavy particles are rejected by the sorting areas, of which three main types are described. Light particles in suspension in the stomach fluid are carried by the circulating current to the vicinity of the opening of the ducts of the digestive diverticula.The form of the primitive polysyringian stomach and the evolution of sorting areas are postulated. Possible steps in the evolution of the gastropemptan stomach through the gastrotetartikan form are suggested. The function of the appendix is that of a temporary store for large, heavy particles which escape the pallial sortingjnechanisms. It is noted that this organ occurs in all three orders of the Polysyrin

ISSN:0370-2774    

DOI:10.1111/j.1469-7998.1965.tb04640.x

出版商:Blackwell Publishing Ltd    

年代:1965

数据来源: WILEY

摘要:

The structure and formation of the cuticle ofGammarus pulexL. is described and is found to be basically similar to that of decapod Crustacea. A scheme for designating stages in the moulting cycle is given. The principal food reserve is lipoid which is stored in the digestive gland and extensive adipose connective tissue. Glycogen is stored only in slight quantities, if at all, in intermoult animals, but appears in connective tissues, muscle sarcoplasm and epidermis during pre‐moult. During pre‐moult the muscle sarcoplasm forms an additional site for storing lipoid, which also appears in the epidermis. Following a moult the quantities of lipoid in muscle sarcoplasm and epidermis, and of glycogen in all sites, decline as the new cuticle approaches completion. Calcium is not stored. Animals fed on an enriched diet will store glycogen in all storage sites during intermoult. It is concluded that the lipoid and glycogen appearing in the epidermis are utilized in the formation of the new integument. The possible function of the tegumental glands in the Peracarida is discus

ISSN:0370-2774    

DOI:10.1111/j.1469-7998.1965.tb04641.x

出版商:Blackwell Publishing Ltd    

年代:1965

数据来源: WILEY

摘要:

Cautery of the cerebral neurosecretory cells in the immature male desert locust results in a retention of water and a consequent dilution of the haemolymph. If such cauterized locusts are given an excess water load this is lost far more slowly than in control animals; further, water is lost at a much slower rate in water loaded decapitated males than in decapitated males given a water load containing neurosecretory material (extract of corpora cardiaca).The histology of the neurosecretory system of the adult male desert locust is in all respects similar to that of the female. In the mature male most of the cerebral neurosecretory cells are histologically “full”, and injection of distilled water into such locusts results in a significant decrease in the number of “full” cells, indicating a release of neurosecretory material. Injection of 10% sodium chloride does not result in any such change.Allatectomy of males results in an accumulation of neurosecretory material in both the cerebral neurosecretory cells and corpora cardiaca. Injection of distilled water into these locusts results in a significant decrease in the number of “full” cells and injection of 10% sodium chloride does not result in any change.These results are consistent with the idea that the cerebral neurosecretory system produces a diuretic factor. However, as yet, no observations have been made of the effects of neurosecretion on the Malpighian tubules and so the possibility that the neurosecretory system is notdirectlyrelated to the general mechanism of water balance r

ISSN:0370-2774    

DOI:10.1111/j.1469-7998.1965.tb04642.x

出版商:Blackwell Publishing Ltd    

年代:1965

数据来源: WILEY

摘要:

In a recent paper Corbet (1963) summarized the occurrence of white hairs in the tail‐tips of a number of species of British mammals using specimens from the collection of the British Museum (Natural History). In the series of 47 house mice referred to by Corbet no white tail‐tipped examples were noted, and I can find no published record of this condition in this species. Between March and May 1964 I collected or received specimens from a number of South Yorkshire coal‐mines and amongst this collection of 94 were seven which showed tail‐tip whitening to some extent. Over 70 of these mice were prepared as cabinet skins with skulls and they have been deposited in the collection of the Doncaster

ISSN:0370-2774    

DOI:10.1111/j.1469-7998.1965.tb04643.x

出版商:Blackwell Publishing Ltd    

年代:1965

数据来源: WILEY

摘要:

The use of the trap‐line in studying small mammal populations has been criticized but it is difficult to design anything so simple to operate and so suitable for naturalists who have little time to spare. The results reported here suggest that the method is quite capable of tracking broad changes of distribution in time and spac

ISSN:0370-2774    

DOI:10.1111/j.1469-7998.1965.tb04644.x

出版商:Blackwell Publishing Ltd    

年代:1965

数据来源: WILEY

摘要:

This note is submitted to record evidence of the harmful effects on small rodents of banding them with metal rings (see Fullagar&Jewell, 1965).

ISSN:0370-2774    

DOI:10.1111/j.1469-7998.1965.tb04645.x

出版商:Blackwell Publishing Ltd    

年代:1965

数据来源: WILEY

摘要:

A difference was noticed in the type of hole made by captive wood mice (Apodemus sylvaticus) and bank voles (Clethrionomys glareolus) when opening hazel nuts. To find the reason for this they were observed when actually opening the nuts.

ISSN:0370-2774    

DOI:10.1111/j.1469-7998.1965.tb04646.x

出版商:Blackwell Publishing Ltd    

年代:1965

数据来源: WILEY