Cap: covered in a slimy mass of dark olive-coloured spores at maturity. Stem: cylindrical, rapidly elongating, white, spongy and hollow. Spore-mass: dark olive-green, smelling strongly, foetid. Spores: small, pale olive, oblong and 3-5 × 2 µm in size. _Habitat_ & _Distribution_: Common from summer to autumn on the ground in woods and in gardens. _General Information_: Easily recognised by its shape and evil smell which can be detected at some distance. The unburst eggs are called ‘witches eggs’. Under favourable conditions the egg bursts and the stem elongates carrying the cap and spore-mass with it. The spore-mass is attractive to flies and they feed upon it; spores stick to their feet and so are transported from one place to another. The very similar _P. hadriani_ Persoon is frequently found in sand-dunes; it differs in having a lilaceous colour to the egg. An interesting variety of the common stinkhorn is uncommonly found and differs in having a skirt-like frill beneath the cap. The jelly in the egg is a water-store and is used by the fungus to expand rapidly. ~Mutinus caninus~ (Persoon) Fries, the ‘Dogs stinkhorn’, is found around old stumps or on piles of leaves. It has the spore-mass covering an orange-red pear-shaped cap which is itself fused to the stem. The stinkhorns and their allies appear to be commoner in warmer countries where they take on many bizarre shapes. Other than the three species noted above stinkhorns are rarely found in this country, but when they are it would appear they have been introduced with foreign imports such as timber, ornamental plants, vegetables etc. Eggs of phalloids brought into the laboratory can be surrounded by wet tissues or blotting paper and then allowed to develop further in a dish or box. Provided the skin covering the spores is not broken or injured the fungus will not smell and therefore before it becomes unpleasant, the whole mechanism of expansion can be studied. _Illustrations_: Hvass 323; LH 215; NB 153¹; WD 108¹. [Illustration: Plate 65. Stinkhorns] Birds nest fungi ~Crucibulum laeve~ (de Candolle) Kambly _Fruit-body_: diameter 8-12 mm. _Description_: Fruit-body: ochraceous brown or sand-colour, downy and then smooth, truncate, cup-shaped with the cup at first closed by a yellowish membrane which finally splits to expose a group of pale brown or dingy whitish, circular, lens-shaped ‘eggs’ (peridioles), scattered on a shiny pale ochraceous interior. Spores: medium-sized, in packets within ‘eggs’, ellipsoid, hyaline, smooth and 8-10 × 4-6 µm in size. _Habitat_ & _Distribution_: Common in crowded groups on dead twigs, fern stems, straw and wheat stubble.