December 1, 1911] 



SCIENCE 



771 



cell-division in cestode cells prompted me to 

 attempt to apply the method of Harrison' in 

 growing neurones, to cultures of cells from 

 the tape-worms which are available from the 

 spiral valve of the dog-fish, sand-shark, the 

 cystic duct of the squeteague, etc. Inasmuch 

 as sand-sharks were obtained only infre- 

 quently during the summer of 1911 at the 

 Marine Biological Laboratory, Woods Hole, 

 Mass., I was forced to depend upon the small 

 Calliobothrium of the dog-fish, rather than 

 upon the larger and more desirable Crosso- 

 hothrium of the sand-shark. The form in the 

 squeteague was not obtained in sufiicient 

 numbers to be of much use in the experi- 

 ments. 



I was directly led to the attempt of growing 

 the isolated cells of the tape-worm from an 

 examination which Dr. Frederic M. Hanes 

 and Dr. E. A. Lambert kindly permitted me 

 to make, of a series of their preparations of 

 mouse sarcoma cells growing in vitro at the 

 College of Physicians and Surgeons, New 

 York. The marked success which they ex- 

 perienced' along this line, where the cells 

 grew out from the small pieces of tissue from 

 the living mouse and exhibited amcsboid loco- 

 motion, absorption of granules of carmin, 

 presence of mitosis, etc., seemed possible in 

 other material. 



The method which was used in the present 

 set of experiments was as follows : Slides 

 with depressions and their covers were ster- 

 ilized in a hot-air oven at 200° C. for ten 

 minutes. Where the plasma of the blood 

 of the dog-fish or sand-shark was used, it 

 was centrifuged after its drainage from the 

 caudal artery under aseptic conditions (can- 

 ula sterilized in olive oil at boiling) in 

 paraffin lined tubes surrounded with freezing 

 mixture and the supernatant plasma was 

 pipetted into cooled tubes which were kept in 

 an ice box until used. The precautions taken 

 to insure sterility were of course aimed at 

 keeping the plasma as free from bacterial de- 



' Harrison, R. G., 1910, Journ. Exper. Zool., 

 9: 787. 



' Lambert and Hanes, 1911, Journ. Am. Med. 

 Assoc, three communications. 



composition as possible and thus offer to the 

 cells of the tape-worm as nearly isotonic a 

 medium for growth as practicable. K Crosso- 

 hoihrium was used as material, the blood of 

 the sand-shark was used; if Callioiothrium, 

 the dog-fish blood. 



The tape-worms were invariably taken from 

 a fish which had just been killed. They were 

 washed off in sterile sea-water, with several 

 changes and finally teased into small bits of 

 groups of cells which were then transferred 

 to a drop of serum laid upon a cover-glass 

 with a platinum loop. The cover was then 

 mounted in vaseline over the depression. In 

 case intra vitam stains were used, these 

 were introduced at once before the prepara- 

 tion was sealed. Inasmuch as I was dealing 

 with a poikilothermous animal and not with 

 a constant temperature, warm-blodded one, 

 as in the work of Harrison, Burrows," Lam- 

 bert and Hanes et al., it was not necessary to 

 keep the slides in a thermostat. The tem- 

 perature, however, varied only from about 

 17° C. to 23° C. 



The cells prepared in this manner began to 

 migrate from the mass within twelve hours 

 and were to be found at the end of that 

 period, or earlier, in some cases, distributed 

 over the whole of the culture medium. I 

 could not observe any true amoeboid motion, 

 as evidenced by the formation of pseudopodia 

 and the streaming of granules, but there 

 could be no other factor operating except the 

 locomotion of the cells as far as I could de- 

 termine. It must be understood that the cells 

 are very small, and exhibit a marked degree 

 of refraction, as is the case with all of the 

 cestodes and even if blunt pseudopodia were 

 formed, they would be observed only under 

 the most favorable conditions, while probably 

 protoplasmic streaming would be impossible 

 to see. Moreover, when the plasma of Limu- 

 lus was used, this distinction of cells was not 

 observed, owing probably to the toxic action 

 of the copper content of this peculiar blood. 



Saline solutions of various content and 

 pure sea-water were also used as media and in 



' Burrows, M. T., 1910, Journ. Am. Med. Assoc, 

 p. 2057. 



