77/(5 Dispersal of Fruits and Seeds by Ants. 25 
(3) . In the Hcpatica type the basal portion of the pericarp is 
transformed into the elaiosome. Examples are Ficaria ranun- 
culoides, Hcpatica triloba, Fumaria capreolata. 
(4) . The Parietaria type has the base of the perigone stored 
with oil. 
(5) . In the Ajuga type the nutlets on separating carry away a 
portion of the floral axis (pseudostrophiole) which with the base of 
the pericarp constitutes the elaiosome. Examples :—several 
Labiatm and Borragineae. 
(6) . In the Aremonia type, to which Thesium, belongs the basal 
portion of the thalamus forms the elaiosome, while this organ is 
formed by the base of the utriculus in the (7) Carex digitata 
type. Finally in a few grasses the elaiosome is formed by a part 
of the inflorescence. This constitutes the (8) Melica nutans type. 
In a number of other cases the plants possess some additional 
means of seed dispersal besides that due to ants. Thus in 
Euphorbia, where we have an elaiosome of the Viola odorata type — 
the seeds are ejected by dehiscence of capsule. This applies to 
some of the species of Viola. In other cases the fruits are more 
or less anemochorous, but possess elaiosomes in addition. Thus in 
several species of Centaurea (C. cyanus, C. dealbata ) ridge-like 
swellings at the base of the fruit are found to contain oil, and these 
fruits are eagerly sought after by ants. In some species of Carduus 
and Cirsium the pappus is lost very early, and the base of the 
style functions as an elaiosome. These and others constitute five 
additional types of Sernander. 
From the examples mentioned above it will be seen that the 
European myrmecochorous plants are largely meadow and woodland 
plants, many of them flowering early in the year and fruiting during 
the period of insect activity. Of the 120 plants which Sernander 
claims as mymecochorous, many show adaptations to this [form of 
dissemination other than the possession of an elaiosome. The 
greater number are found to have a comparatively poor supply of 
mechanical tissue in their flowering axis, which, after the flowering 
period, becomes limp and bends down so that the capsule often 
opens on the ground. This is the case for example in Scilla 
sibirica, Anemone hepatica, Ranunculus ficaria, Viola odorata, while 
allied species which are not myrmecochorous produce their flowers 
on erect inflorescences. Of course in the case of plants which 
combine anemochory with myrmecochory the fruiting axis always 
remain erect. 
