MORGULIS. — DEVELOPMENT OF TOXOPNEUSTES VARIEGATUS. 139 



Since my results did not agree with those obtained from the similar 

 investigations of my predecessors, and since they are derived from 

 entirely different species, I repeated the experiments with atropine 

 and pilocarpine a great many times, but always with the same result. 

 Although a small reduction in the size of embryos did occur, there 

 was no increase of size nor acceleration of the development under the 

 influence of pilocarpine. 



The suggestion has been made that atropine and pilocarpine respec- 

 tively inhibit and accelerate the oxidizing processes going on in the cells, 

 thus causing either a decrease or an increase in the size of the embryos. 

 It might he expected, therefore, that a mixture of appropriate quan- 

 tities of atropine and pilocarpine would neutralize each other's action . 

 In none of my own trials have I succeeded in neutralizing their effects, 

 but, as had been already observed by Sollman, the depressive action 

 predominates, and the embryos show a greater tendency to die out 

 in the mixture than in either atropine or pilocarpine alone. In all of 

 my experiments the larvae developing in the mixture of atropine and 

 pilocarpine were intermediate in size as compared with those develop- 

 ing in either of those solutions alone. This will be seen from Table III. 



Experiments with Morphine Sulphate. 



Eggs were placed in sea-water with various quantities of a 0.5 per 

 cent aqueous solution .of morphine sulphate soon after they had been 

 fertilized. In none of the experiments, save those where the concen- 

 tration proved directly injurious, has there been an influence exerted 

 upon the developing eggs during the segmentation stages, the effect 

 becoming apparent after the first day only. In sea-water with but 

 tV t° 20 °f 1 c - c - °f * ne standard morphine solution (0.5 per cent) to 

 each 100 cc. the rate of development as well as the size of the larvae 

 remained absolutely normal, but in concentration of £ to J cc. of the 

 morphine solution to 100 cc. of sea-water the size of the developing 

 embryos suffers a slight, though noticeable reduction. The segmen- 

 tation, however, is perfectly normal. With stronger solutions the 

 effect becomes more pronounced, of course; and when 1 cc of the 

 morphine solution is added to 100 cc of sea-water the effect is no 

 longer limited to the size of the plutei, but is seen also in a general 

 slowing of the developmental process. In solutions two and three 

 times that strength cleavage is very much retarded and is quite ab- 

 normal. In the following Table (IV) are given the records pertaining 

 to the concluding experiment with various strengths of the mor- 

 phine solution. 



