Some hydathodes also are capable of absorbing as well as excreting water.
They also assist saprophytes by excreting useful minerals such as urea, and by aerating the soil.
Undernutrition is a consequence of consuming little energy and other essential nutrients, or using or excreting them more rapidly than they can be replaced.
If, for instance, we find that instead of the natural number of Malpighian bodies in the kidney there are only half that number, then we are entitled to say that this defect represents disease of structure; and if we find that the organ is excreting a new substance, such as albumen, we can affirm logically that its function is abnormal.
Embedded in the incurved margin of the rim which affords a very insecure foothold to insects, are a number of large glands excreting a sweet juice.
