ISSN:0370-0461    

DOI:10.1111/j.1095-8312.1965.tb00932.x

出版商:Blackwell Publishing Ltd    

年代:1965

数据来源: WILEY

ISSN:0370-0461    

DOI:10.1111/j.1095-8312.1965.tb00933.x

出版商:Blackwell Publishing Ltd    

年代:1965

数据来源: WILEY

摘要:

SUMMARY.The cephalic septum in the Ascaridoidea, which forms a transverse sheet of tissue at the level of the anterior end of the oesophagus and cuts off the lips from the general pseudo‐coelom, contains three fibre systems. One system runs anteriorly between the anterior end of the body musculature and the body cuticle at the base of the lips, one runs transversely between the body‐musculature and the anterior end of the oesophagus, and one transversely between the anterior end of the oesophagus and the cuticle at the base of the lips. The fibres have probably developed as a direct response to the stresses between the oblique muscles at the anterior end of the oesophagus, which open the lips, and the body wall during the development of both the larval and adult stages. In association with the appearance of the three large lips characteristic of the more advanced members of this superfamily, both developmentally and phylogenetically, the oesophagus has become increasingly removed from its primitive or earlier position close to the anterior end of the body and, concomitantly, from near the body musculature. The cephalic septum has developed from hypodermal tissue to give the oesophagus a support which has become transferred with the increasing size of the lips from the body musculature and its associated oesophageal fibres to the oesophagus: cuticle fibre system. It is postulated that this shift parallels a change in the function of the lips from gripping to passing food to the anterior end of the oesophagus.The lips are controlled by the oesophageal muscles, the increase in size of the lips is due to elongation of a restricted number of cells and the body musculature always remains slightly posterior to the anterior end of the oesophagus. It is argued, therefore, that the development of the buccal cavity is due to a process of elongation and that because the body musculature does not take part in this anterior growth the cephalic septum is required to enable the oesophageal musculature to control the opening and closing of the lips. It is further pointed out that if such conditions apply in the Nematoda as a whole, so that some remote control system is required to open the mouth in complex forms, this must impose restrictions on the possible forms the mouth opening can t

ISSN:0370-0461    

DOI:10.1111/j.1095-8312.1965.tb00934.x

出版商:Blackwell Publishing Ltd    

年代:1965

数据来源: WILEY

摘要:

SUMMARYTwo faunas and floras from horizons in the alluvium of the River Bourne, Warwickshire, have been investigated with especial reference to their ecological implications. It is shown that much information on the past ecology of the area can be obtained from the plants and animals, whose independent evidence agrees closely.About 5000 years ago (Site A) the area was completely forested, mainly byAlnuswoods on the wet alluvial soils andTilia‐Quercus‐Ulmusforests on the dry fertile soils of the hill slopes. This distinctive association contained bothTilia cordataandT. platyphyllosand is thought to have been fairly extensive. The insects and mammals are dominantly forest species with many specifically associated with the trees present, including aTiliafeeder no longer native to Britain(Ernopocerus caucasicus).A relatively swift‐flowing small stream in the valley had its own aquatic and semi‐aquatic flora and fauna.During a much later period, approximately 400 years ago, (Site B) the area was largely devoted to agriculture, both arable and pastoral, which was accompanied by a large weed and ruderal flora and phytophagous and coprophagus insect fauna. Of the phytophagous Ooleptera 93 per cent are associated with plants recorded. Elsewhere open woods and scrub were present with a fauna of woodland insects. Other plants and insects existed in and beside a more slowly flowin

ISSN:0370-0461    

DOI:10.1111/j.1095-8312.1965.tb00935.x

出版商:Blackwell Publishing Ltd    

年代:1965

数据来源: WILEY

ISSN:0370-0461    

DOI:10.1111/j.1095-8312.1965.tb00936.x

出版商:Blackwell Publishing Ltd    

年代:1965

数据来源: WILEY

ISSN:0370-0461    

DOI:10.1111/j.1095-8312.1965.tb00937.x

出版商:Blackwell Publishing Ltd    

年代:1965

数据来源: WILEY

ISSN:0370-0461    

DOI:10.1111/j.1095-8312.1965.tb00938.x

出版商:Blackwell Publishing Ltd    

年代:1965

数据来源: WILEY

ISSN:0370-0461    

DOI:10.1111/j.1095-8312.1965.tb00932a.x

出版商:Blackwell Publishing Ltd    

年代:1965

数据来源: WILEY