or OrdeaUBean of Old Calabar, 391 



The pup<s belong to the class Incased of Burmeister, are 

 about |ths of an inch in length, and of a yellowish-brown co- 

 lour. The cocoons are greyish white, and always covered with 

 entangled excrement. Sometimes one pupa only occurs in a 

 bean, at others as many as four. In a few instances, cocoons 

 were found with perfect pupse ; in general they contained only 

 the cases of the developed imago. 



We have thus the changes of the complete metamorphosis of 

 an insect unequivocally traced ; and, through the kindness of 

 my friend the Rev. John Baillie, the perfect and several imper- 

 fect forms of the imago of this insect have been put in my pos- 

 session. All of these were derived in a manner which com- 

 pletely precludes the chance of any error. From the same lot 

 of aflFected beans that are described above, a number of cater- 

 pillars were selected at Old Calabar, and placed in a box along 

 with several perforated beans. Cocoons were observed to be 

 rapidly formed, and in a few days four or five live moths were 

 obtained. I am indebted to my friend Dr. John Anderson, of 

 this city, for the identification of this moth. Specimens of the 

 caterpillar, cocoons, and imago were kindly sent by him to the 

 British Museum, and were pronounced by the authorities of the 

 Insect Department to be the Deiopeia pulchella (order Lepido- 

 ptera, fam. Tineidse, Leach). The description and figure given 

 in the fourth volume of Curtis^s * British Entomology' appear to 

 correspond accurately with the imago in my possession. 



Little beyond conjecture can be advanced on the method of the 

 introduction of this insect into the Calabar beans. The holes 

 in the spermoderm have always a sharply defined margin, which 

 opposes the idea of a deposit by the ovipositor of the imago into 

 the unripe and growing kernel ; and the distance from the 

 exterior of the mature pod to the seeds renders it still more 

 improbable that the imago could reach the ripe beans for such a 

 purpose. The most probable view is that the ovum is deposited 

 in the cellular texture beneath the soft exterior of the young 

 pod, that it is there hatched, and that thence the caterpillar makes 

 its own way to the interior of the bean. It is perfectly able to 

 perforate the hard spermoderm of the ripe seed, and has been 

 observed to do so ; indeed it has been known to make holes of 

 considerable depth into a hard wooden board. 



The Ordeal-bean of Calabar is a poison of extreme activity : 

 hitherto no living being had been known to be able to resist its 

 action ; and, from my knowledge of its properties, I confess to 

 having been sceptical of the existence of any animal form which 

 could be fairly subjected to its influence and still retain its hold 

 on life. It appeared of importance to determine, as exactly as 

 possible, the connexion between this caterpillar and the kernel of 



