184 



SCIENCE. 



[Vor,. II., No. 28. 



In the winter of 1878, being near Depot Is- 

 land In North Hudson's Baj-, we moved into 

 igloos on the 1st of No>ember. On King Wil- 

 liam's Land, next spring, we abandoned snow- 

 honses, and took to tents on the 17th of June, 

 having lived an igtoo-life for seven months and 

 seventeen days. That winter upon King Wil- 

 liam's Land we reared our first igloo on the 

 25th of September, being one month and five 

 days earlier than at Depot Island the previous 

 season. This would give a total of igloo-life 

 for the southern part of King William's Land 

 of eight months and twenty-two days, or nearly 

 three-fourths of the year. This is the nearest 

 to the pole of greatest cold (be it the magnetic 

 pole or according to Bent) that anj- white men 

 have lived d, la Innuit. Assuming these two 

 physical poles to be identical, and our posi- 

 tion having been so near them, — being really 

 onl}" about a hundred miles distant, — • we 

 must have experienced about the maximum 

 of annual igloo-life. Returning to North 

 Hudson's Bay in the spring of 1880, we, as 

 well as the majority of the Esquimaux liv- 

 ing around Depot Island, moved into tents 

 about the middle of May, giving igloo-life 

 for North Hudson's Bay something over half 

 the year, which is probablj' near the mini- 

 mum. 



While, of course, climatic causes principallj' 

 determine the annual longevity of the snow- 

 house, they are not the only ones. As soon 

 as the spring thaws commence tumbling in 

 the igloos, or making their structure insecure, 

 the native would gladly avail himself of a tent ; 

 but this he cannot dp, unless there be a clear 

 spot somewhere near, on which it can be 

 pitched. It may be a number of days from 

 tlie time he woukl accept tent-life before the 

 hilltops or ridges commence peeping through 

 their winter covering. The inland ridges, 

 higher and more marked, covered with black 

 moss, which, once through the crust, makes sad 

 havoc with the snow, appear much sooner than 

 those facing the sea, which are flatter, enal)ling 

 the inland reindeer hunters to occupy their tents 

 earUer than the seal or walrus hunters of 

 the coast. Some igloo-builders will wait until 

 they can kill enougli seal to make a new tent 

 before using one. The Ooqueesik Salik 

 Esquimaux of the Dangerous Rapids of the 

 Great Fish River can be said to be practically 

 without tents, securing nothing, or almost 

 nothing, from which to make them. They hold 

 to the shelter of an igloo late in the spring, 

 and seek it as soon as one can be made in the 

 early winter. 



{To be continued.') 



ON THE DEVELOPMENT OF THE PIT- 

 UITARY BODY IN PETROMYZON, AND 

 THE SIGNIFICANCE OF THAT ORGAN 

 IN OTHER TYPES. 



In the Quarterly journal of microncopical 

 science (xxi. 750) I published a brief prelimi- 

 nary account of the development of the pituitary 

 body in the lampre}', stating that it was formed 

 from a part of the nasal sac. This account 

 of a method of formation so entii'ely different 

 from any thing that was known among the -vei-- 

 tebrates was received with incredulity by Bal- 

 four, who says (Comp. embryology-, ii. 358), 

 "I have not mj'self completely followed its 

 development in Petroniyzon, but I have ob- 

 served a slight diverticulum of the stomodaeura 

 which I believe gives origin to it. Fuller de- 

 tails are in anj* case required before we can 

 admit so great a divergence from the normal 

 development as is indicated by Scott's state- 

 ments." These fuller details have long been 

 nearly ready for publication, but I have been 

 prevented by circumstances from issuing them. 

 I hope shortl}' to continue my series of studies 

 on the embryology of Fetromyzon, but, in the 

 mean time, think it advisable to present this 

 preliminarj- account. 



My friend, Dr. Dohrn of Naples, has lately 

 investigated this subject, and has come to the 

 conclusion that neither Balfour nor myself can 

 be correct, but that the pituitary bod}' arises 

 from an independent invagination of the epi- 

 blast between the nasal epithelium and the 

 mouth {Miltli. zool. stat. Neapel, iv. 1 heft). 

 On examining Dohrn's figures, however, I was 

 much pleased to find that his disagreement with 

 me is rather about terms than facts ; for these 

 drawings correspond almost exactly with those 

 that I have already published, and manj' more 

 as yet unpubUshed. 



Fig. 1 Snsittiil section through liead of l.ttnproy embryo, m, 



motitli; pi, pittiitiu-y invagination; In, infunilibulum; //y, 

 hypoblast of tluxiat; cA, notocbord ; /, upper lip. 



The development of the pituitarj' body, as far 

 as I have been able to trace it, is as follows. 

 Shortlj' before hatching, the mouth is formed by 

 a deep iuvaginatipu of the epiblast (see fig. 1 , 



