August 8, 1890.] 



SCIENCE. 



79 



tive processes. The laws of atrophy and final disappearance of 

 disused organs, so ably advocated by Darwin, are equally striking 

 with regard to individual tissues and cells, and it is a vpell-recog- 

 nized fact that tbehigher the original development of a tissue or 

 cell has been— i.e., the more it has been differentiated or special- 

 ized from the amoeba type — the more profoundly is it affected by 

 alterations in environment or nutrition, so as to degenerate com- 

 pletely, or be replaced by some form of tissue like the connective, 

 ■which is of lower development but stronger vitality. The result 

 of nerve grafting and of nerve suture after complete section have 

 varied greatly in the hands of different operators, but, despite 

 many discouraging failures, there is no doubt that in man, as well 

 as in the lower animals, nerve fibres may reunite when sutured 

 even after secondary degeneration has occurred, and they exhibit 

 restoration of function. For this to occur, however, the nerves 

 must be in communication with some trophic centre. Nerve 

 grafting does not succeed so well as nerve sutures in favorable 

 cases. It occurred to Dr. Thompson recently, while studying 

 cerebral localization in the lower animals, that it would be inter- 

 esting to graft a piece of brain tissue from one side of a dog's 

 brain to the other, or from one animal's brain into another's, and 

 study its vitality. Of course, he had no expectation of being able 

 to restore abolished function by the operation, but the question of 

 vitality of the brain tissue and the course of its degeneration is a 

 subject .which is of very wide interest. The first experiments 

 were preliminary, made in order to ascertain whether the trans- 

 planted brain would be immediately absorbed or would slough 

 away. 



No microscopic examination was made in coim^ection with these 

 experiments, as it was intended only to determine the possibility 

 of the transplanted tissue adhering. Being satisfied in regard to 

 this matter, Dr. Thompson secured a large dog and performed his 

 experiment. A half-inch trephine was used and a button of 

 bone was cut nearly through over the left occipital region, leaving 

 a small attached margin so that the button could be elevated and 

 then depressed like a little trap-door. Through the opening 3 c.c. 

 of brain tissue were removed. A cat was simultaneously tre- 

 phined and 1.5 c.c. of brain from her left occipital region were 

 transferred in eight seconds to the opening in the dog's brain. 



The features of interest of this experiment are the facts that: 

 1. There was complete union, through organized connective tis- 

 sue, of the contiguous portions of the two brains. 3. After seven 

 weeks the oat's brain still maintained enough vitality to be dis- 

 tinctly recognized as brain tissue. 3. Brains of animals of two 

 very different species were thus made to unite. 4. The cat and 

 dog pias presented perfect union as well. 5. There was a sympa- 

 thetic degeneration of the corresponding convolutions upon the 

 ■opposite side of the dog's brain. For this curious fact Dr. Thomp- 

 son can not account. He had never noticed it before, in as many 

 as fifty operations upon this region of the brain of cats and dogs, 

 although he had sometimes seen removal of a part of the occipi- 

 tal region result in extensive softening of the entire hemisphere of 

 the same side. The opposite degeneration in this case may possi- 

 bly be a mere coincidence; if so, it is a very unusual and remark- 

 able one. There was no meningitis to favor it. 6. There was de- 

 scending secondary degeneration of the dog's brain on the side of 

 the graft, as is usual in cases of simple excision of brain cortex ; 

 hence the cat's cortex had not succeeded in acting as a nutrient 

 •centre for the dog's brain. 



Dr. Thompson thinlis the main fact of this experiment— namely, 

 that brain tissue has sufficient vitality to survive for seven weeks 

 the operation of transplantation without wholly losing its identity 

 as brain substance — suggests an interesting field for further re- 

 search, and he has no doubt that other experimenters will be re- 

 warded by investigating it. 



LETTERS TO THE EDITOR. 



Temperature in Storms, and High Areas. 



There are two classes of cases in which the temperature is 



liigher on Mount Washington than at surrounding stations at a 



lower level. By far the most frequent of these is when the crest 



<of an anti-cyclone has just passed that locality. For example, on 



May 33, 1887, at 7 a.m., the temperature on Mount Washington 

 was 58°, with fair weather, and wind velocity 36 miles, from the 

 north-west. At Portland the temperature was 52°, at Boston 56°, 

 at Eastport 44°, at Montreal 44°, the winds being from the south- 

 east and light. The isobar 30.40 was over Nova Scotia, and that 

 of 39.90 was over Lake Superior. On Feb 36, 1887, at 7 a M., 

 New England was enclosed by the isobar 30.40, a low centre, 39.40, 

 being over Wisconsin. The temperature on Mount Washington 

 was -1-8°, at Portland +2°, at Montreal —10°, at Albany +8°, 

 and at Eastport +3°. On Feb. 3, 1887, the isobar 30.90 was 

 located directly north of New England, and there was no low 

 centre nearer than Utah and Colorado. The temperature on 

 Mount Washington was 4-5°, at Portland +i°, at Eastport —3°, at 

 Montreal —10°. On March 6, 1887, the temperature on Mount 

 Washington was 15°, at Portland 14°, at Eastport 15°, and at 

 Quebec 7°. The isobar 30.60 appeared in Nova Scotia. On Dec. 

 31, 1886, at 7 a.m., the isobar 80.60 was located in Nova Scotia, 

 and that of 39.80 in Tennessee. The temperature on Mount 

 Washington was +9°, at Portland H-3°, at Montreal —7°, with 

 winds generally from northerly points except on Mount Washing- 

 ington, where they were frojn the west. On Dec. 36, 1886, the 

 isobar 30.40 was over Maine, and that of 39.80 over the upper 

 lakes; temperature on Mount Washington +14°, at Portland 

 +10°, at Montreal -3°, at Albany +13°, at Boston +15°. On 

 Jan. 17, 1887, at 7 a m., the isobar 30.50 was over the maritime 

 provinces, and 39.30 over Michigan; temperature +30° at Mount 

 Washington, +8° at Portland, and +17° at Albany. On Jan. 4, 

 1887, at 7 A.M., the isobar 30.70 enclosed New Hampshire, south- 

 ern Vermont, and south-eastern New York. Within these limits 

 at the very crest of the anti-cyclone the temperature on Mount 

 Washington was —1°, at Portland —7°, and at Albany —4°. 



Numerous other instances of the kind might be cited, and the 

 list might be greatly enlarged also by admitting cases in which an 

 approach to inversion of temperature was apparent although not 

 fully attained. _ 



The other class of cases in which there has been an inversion 

 of temperature are much more rare and difficult to define, being 

 due apparently to temporary anomalous conditions of one sort or 

 another. For example, on Jan. 10, 1887, at 7 a.m., the tempera- 

 ture on Mount Washington was +10°, at Portland +8°, at Bos- 

 ton + 14°, and at Eastport +30°, although a low centre sur- 

 rounded by the isobar 39,50 was located in Maine. The isobar 

 30.00 appeared over New Brunswick, as in the previous cases, 

 however, and the isotherms were very much crowded, there being 

 a gradient of 30 degrees' between Nova Scotia and New Bruns- 

 wick. In hke manner on Dec. 16, 1886, there was a low centre, 

 39.50, off the New England coast, and an unusually confused ar- 

 rangement of the isobars and isotherms toward the north-west, a 

 low centre, 39.80, being over Lake Huron, with the isotherms 

 + 50° over Nova Scotia and —10° near Rockliffe, Canada. Coin- 

 cidentally with this anomalous condition the temperature was 

 somewhat higher on Mount Washington than at surrounding sta- 

 tions. ■ i 

 As a rule, however, increased divergence of temperature be- 

 twixt Mount Washington and surrounding stations attends and 

 follows the passage of cyclonic centres. For example, on April 

 30, 1887, the isobar 39.30 covered portions of Maine and New 

 Hampshire, this being the very centre of the low area. On 

 Mount Washington the temperature was 36°, at Portland 46°, at 

 Boston, 50", at Montreal 39°, at Albany 43°, gradually decreasing 

 westward to the lake region, where an anti-cyclone was located. 

 On March 35, 1887, at 7 a.m., the centre of a cyclone was exactly 

 over New Hampshire, with pressure 39.30, and temperature on 

 Mount Washington 4-30°, at Portland -|-39°, at Montreal -f35°, at 

 Quebec +38°, at Boston -f 46°, at Albany 4-35°. On Sept. 8, 1887, 

 at 7 A.M., a low centre, 39.40, was at Father Point, Canada, and 

 the barometric trough extended thence south-westward into 

 Maine. At Mount Washington the temperature was 3S°, at Port- 

 land 60°, at Montreal 54°, and at Quebec 53°. With the distribu- 

 tion of pressure just described, wide divergence of temperature 

 between Mount Washington and surrounding stations is extremely 

 common, and it is not necessary to multiply illustrations. The 

 contrast with the comparative equalization of temperature Jat 



