342 THE JOURNAL OF BOTAMT 



The following remarks by J. G. Wood (Insects at Home, p. 616 ; 

 1872) are of interest ; they seem to have escaped the attention of 

 botanical writers, no doubt owing to their appearance in an entomo- 

 mological work : — " A warm spring day is the time in which the 



Humble-Bee Fly may geuerally be seen Whenever I wanted 



to catch a Bombylius I used to look out for a patch of Primroses on 

 which the sun was shining, and to wait there with the net placed 

 close to the flowers in readiness for a stroke. After waiting some 

 little time, and taking care not to make the slightest movement, 

 a Bombylius was nearly sure to come to the flower, and hover first over 

 one and then over another as if to ascertain which blossom contained 

 the most honey. Having at last fixed upon a flower it would plunge 

 its proboscis into it and then a quick stroke of the net would 

 secure it." 



It has^ not, I believe, previously been remarked that the time 

 during which B. major and B. discolor are in evidence coincides to a 

 remarkable degree with the flowering period of the Primrose: both 

 are early vernal insects, disappearing by the end of May. Verrall 

 (op. cit.) gives March 15 to May 17 as the period of B. discolor, 

 while the commoner species ranges from March 27 to May 27. It 

 may be added that the two remaining British Bombylia are summer 

 insects, and do not emerge until the Primrose season is past. LuciUa 

 vcesar and Hyetodesia lucorum, which were noted as visitors at 

 Llanfvnydd, did not visit the flowers in the systematic manner of 

 Bombylius. Sometimes they fed on pollen of short-styled flowers, 

 while at other times they seemed to regard Primroses as convenient 

 resting-places on which to bask. The nectar was, of course, inac- 

 cessible to these, though they may be occasional agents in pollination. 

 Owing to lack of previous night observations, Gasteropoda have 

 not been hitherto recorded as Primrose visitors, but nocturnal watch- 

 ing shows _ that they are not infrequent. The flattened corolla-limb 

 and the slightly projecting stigma or stamens are features conducive 

 to pollination by snails or slugs. It is not uncommon to find these 

 creatures crawling over the corolla at night time and feeding on the 

 floral organs, when the head and the slimy surface of the foot 

 commonly come into contact with the stamens or stigma, as the case 

 may be, in the mouth of the corolla. When the animal is on a short- 

 styled plant, pollen-grains commonly adhere to it, and these may be 

 transferred to stigmas of adjoining long-styled plants. Transference 

 of pollen from long-styled to short-styled flowers may also occur, 

 but I think effective pollination in this way is unlikely. On the 

 other hand, snails and slugs may readily contribute towards autogamy 

 in the case of short-styled flowers. 



_ Knuth (/. c.) only mentions three European plants (Calla palus- 

 tris, Ghrysosple ilium altemifolium, and Chrysanthemum Leucan- 

 themum) for which snails or slugs have been recorded as pollinating 

 agents. Ludwig (Sitz-Bericht Gesellsch. Nat. Freunde, 1889, p. \T) 

 observed numerous slugs (Li max I avis Midi.) on the capitula of 

 C. Leucanthemum, where he states that they greedily devoured the 

 Avhite ray florets. The latter considered that slugs may in Avet 

 seasons, when usual pollinating agents are commonly inactive, be 



