THE PITUITARY BODY 147 



must be left in the hands of the student of the reproductive 

 system." 



Recading Heape's work carefully leaves us with the impression 

 that he recognised the switching off of the endocrines from a growth 

 producing function to a gonadotropic function ; but the work of 

 Parkes and others on the gonadotropic function of the anterior lobe 

 of the pituitary was after his time. Nevertheless, on the eel he says, 

 " comparison with a great variety of other animals and especially 

 of fish induces me to hold a strong opinion that development of the 

 reproductive glands and cells is due to a switching off of energy 

 which was previously engaged in those metabolic processes which 

 result in growth." 



Our earliest knowledge of the functions of the pituitary were 

 connected \\ith. growth in certain pathological conditions, and it 

 is now known that in mammals the anterior lobe secretes a growth 

 hormone wliich produces, if in excess, gigantism in chilch'en, and 

 in adults acromegaly. Extracts of the pars distalis in mammals 

 causes growth to take place when it has ceased as the result of the 

 removal of the pituitary. 



It is interesting to note the condition analogous to gigantism 

 in those eels that have been prevented from making the gametic 

 migration. To quote Roule, " not all the eels set out on this 

 hazardous journey. Some at the period of puberty cannot from 

 the nature of the locality leave the lake or the pool in which they 

 are too closely imprisoned. Like the sterile trout of the deep 

 lakes, and for the same reason, their ovaries, for these eels are 

 usually females, change and atrophy. Rendered sterile and 

 natm-ally castrated like pullets they grow fat in the same way, 

 but go on living and growing larger. Eunuch eels of this sort have 

 been kept in captivity for twenty or tliirty years." 



I am informed from a keen and scientific fisherman that he has 

 seen eels of this kind in New Zealand tliree feet or more in length 

 with the girth of a man's thigh. We have made arrangements 

 so that at the earliest opportunity, the pituitary of a " eunuch " 

 eel will be examined, and we look forward to some interesting 

 findings. 



It is now possible to review the colour and other changes that 

 precede the migration of the eel in relation to the activity of the 

 pituitary body. The colour changes have been shown to occur 

 some time before the actual migration and at the same time the 

 posterior lobe enters on a stage of activity as shown by the increase 

 of colloid secretion. 



The anterior lobe may be the cause of the exophthalmos, as it is 



