Section 150. Foreign companies, upon complying with the conditions herein set forth applicable to such companies, may be admitted to transact in the commonwealth any kinds of business authorized by this chapter, subject to all general laws now or hereafter in force relative to insurance companies, and subject to all laws applicable to the transaction of such business by foreign companies and their agents; except that no foreign stock company may issue participating policies unless specifically authorized to do so by its charter or by the laws of its state or government; provided, that no provision of law which by its terms applies specifically to domestic life companies shall thereby become applicable to foreign life companies; and provided, further, that the provisions of section eighty-one relative to the contingent mutual liability of members shall not apply to any foreign mutual fire company which had been admitted to transact business in the commonwealth prior to January first, nineteen hundred and twenty-one and was then actually transacting business therein without complying with said provisions.