Зоология на английском. Обязательный материал для чтения на занятиях и дома. Сологуб Л.И. - 18 стр.

UptoLike

Составители:

Рубрика:

overhanging lip нависающая губа

prostomium простомиум

matter вещество

alimentary canal пищеварительный тракт

semitransparent полупрозрачный

anus задний проход

III. Answer the following questions.

1. What is a worm made up of?

2. What is the difference between the anterior and posterior ends of a worm?

3. What is the function of the bristles?

4. Why is it difficult to find the mouth of a worm?

5. What does the prostomium serve for?

IV. Make up a list of words used to describe the structure of earthworms .

V. Give a short account of

1. the structure of a worm;

2. the process of digestion in a worm.

Text 11

I. Read the text and say what information it carries.

THE EFFECT OP EARTHWORMS ON LITTER DISAPPEARANCE

The development of surface organic horizons Is often attributed to the

absence of earthworm activity. In many cases other factors are more important

but the classical experimental plots of Park Grass, Rothamsted provide an

example where the effects of earthworm activity may be fairly clearly defined.

As a result of repeated applications of ammonium sulphate the acidity of some

plots has eliminated the earthworm population completely and a thick mat of

dead vegetation has developed. It has been suggested that the mat of partly

decomposed herbage which accumulated was formed because the intense acidity

of the soil retarded the decay of organic matter. This is evidently only part of the

explanation, for when the organic matter. This mixed with the soil it

decomposes readily. Probably the primary cause of the formation of a "mat" in

these plots is the complete absence of worms(to pull the dead herbage into the

soil. A comparable accumulation of organic matter in an orchard under grass

occured where the earthworm population has been poisoned by copper sulphate